Following hot on the heels of its release, the Chief Scientist appeared on ABC TV’s Q&A program. Along with some politicians and consumer advocates, the opportunity to discuss some details about the report and the energy market generally.
Look, I don’t generally watch Q&A; what started out as a great premise – get politicians in front of the public to make them answer questions on live, national TV – soon turned into this:
The best episodes were those featuring scientists with no politicians. No surprises there. Any episode involving politicians soon turned into a battle of wits between unarmed opponents.
While there were politicians on last night’s showing (one from each major party), the key inclusions were from the consumer advocacy sector.
Voice Of The Consumer
Amanda McKenzie is CEO of the Climate Council. Formed via crowd funding, after the Climate Commission was abolished by the current government.
Rosemary Sinclair is the CEO of Energy Consumers Australia. ECA aims to provide a voice for residential and small business consumers of energy. Of particular concern to their mission is fair pricing, and reliability.
Of particular interest to ECA is ongoing survey of Energy Consumer Sentiment. This is key to understanding the market as it affects users.
While the two politicians sought to score points, both the CEOs on the panel stayed above the petty bickering. The refreshingly factual dialogue on what consumers want should serve as a reminder to our politicians that their role is to represent us.
The discussion moved to CCS (Carbon Capture and Storage), which seems like a good idea until you look at the economics. Like a lot of fossil-fuel related initiatives, it seems great until apples are compared to apples, as McKenzie said: new renewables beat new fossil fuels.
The Finkel Report, and the man himself, argue that any approach should be tech-agnostic. Therefore we must assume any initiatives that come out of this are economically sound. Coal – in any guise – simply isn’t, even before the healthy impacts are measured.
The most important part of the night were Rosemary Sinclair’s closing remarks. It really sums up our frustration, both at a consumer level for certainty on pricing, and for industry in terms of investment.
We will see where this goes. Hopefully governments at State and Federal level, in light of the Finkel Report, drop the partisanship and legislate for the network we deserve.
As I mentioned on twitter, I’ll be attending Renewable Cities in Sydney this week.
With the release of the Finkel Report so close, I predict there will be a lot of interesting discussion. The goal of the forum is to merge minds on the way forward for our ever-expanding cities and towns.
There are workshops on EVs, a few people like Reposit Power will be there, and I’m looking forward to having a chat to people as I seek out the next stage in my career.
I’ll also bang out a few Twitter Live experiences so make sure you’re following @AuPowerwall!
I’ve been a bit busy to monitor my usage regularly, of late. Feeling out of touch, I made a point of checking my solar generation after recent rainy weeks.
It seemed a little low. Usually I hit 5kW around the middle of the day, but was peaking out at 4.6kW. I was contacted by someone who lives nearby with a corresponding fall in numbers.
The only theory we have to go off is lower angle of the sun. Additionally, because there were two weeks of Autumn where we almost never saw direct sunlight, we didn’t see the slow decline over time.
Its like seeing someone’s kids only occasionally – can’t believe how much they’ve grown! Their parents see it every day.
Having not checked anything for a while, I headed over to the SolarEdge Monitoring Portal to compare their results to Reposit. Having a second source for comparison is very helpful to sort out any discrepancies.
Well, there certainly have been some changes! And all of them look like winners.
The first noticeable change was the new Monthly profile for Power and Energy.
There was a period where the “self-consumption” figure wasn’t being reported through some conflict with the Reposit interface. That’s back, which is great.
Added to this is the “From Battery” stat which is quite cool. It features both in the Consumption summary figure, and the bar graph. This is only recent, so I look forward to that percentage figure “from batteries” smoothing out with a larger data sample.
If you mouse-over any of those bar graphs it gives you the details, in kWh, for the days that have been completed. Again – very vool.
I also hadn’t given much thought to the year-on-year comparison before I had enough data. Now its very handy to answer questions I and my near-neighbour have about long-term performance.
For reference, the figures are in the table below for the three months with suitable data.
* As of April 24.
What I find really interesting is the March figure; despite having an extra 1.5kW of panels this March compared to 2016, the weather meant I didn’t generate quite as much.
Moving forward, I’m sure subsequent years and months will prove to be most interesting. I love me some data!
Live Baby Live!
They’ve also updated the Overview panel to have near-real-time feeds of consumption. I did a quick screen cap of this and stuck it on my YouTube Channel. I like.
All in all, a great round of SolarEdge Updates as we move toward the cooler months.
Finding time to sit and think has been a bit hard. At the same time, there is so much happening here in Australia with regards to renewable energy, its difficult to keep up!
So here’s a scatter gun approach to energy blogging:
Part 1 of this is a scam warning. A group listed “50% OFF!” specials for LG panels and LGChem batteries here recently. One example:
Now, nobody in their right mind should be writing 7.2kw’s as that’s just bad grammar.
Second issue is they’re using a lower case “w” to represent “Watt” for both panels and battery, which is wrong in every scientific manner.
Third issue is the battery is listed as “kw” instead of “kWh” – always remember that batteries are energy storage. This means they should always be listed with their kWh (kilowatt hour) figure to understand.
Beyond all that, the pricing is just cray-cray, and so is the manner of billing. A friend of mine contacted them and they sent him an invoice for the full $12,990. This is weird as most equipment sales would take a deposit (maybe as little as $1000), instead of the full amount to get started.
As it is, he cold-called LG Australia directly, who were aware of it, but couldn’t say much for legal reasons. He also dug a little deeper on the website with the original promotion to see what he could turn up.
Both leads turned him onto the fact that this wasn’t all that it seemed, so he backed right off. Good move.
Several people I’ve talked to in Canberra (our nation’s capital) are saying the phone is off the hook from government offices.
Suddenly people are realising that a smart, integrated grid is a thing we need. The people in power are starting to come around to the fact that coal is going to collapse, and that idiot behaviour about it needs to stop.
That is the Australian Federal Treasurer, waving a lump of coal around in our House of Representatives.
Of course, politicians are populists by nature these days, so it remains to be seen whether talk of batteries survives the Next Big Issue they invent.
New Hydro Stuff
And from the book of “Hey! I’m a Populist, too!” comes our own Prime Minister. He’s decided that expanding our big hydro power scheme in The Snowy Mountains* is an awesome idea, and is framing it as “nation-building”
* some of the place naming in Australia is not wildly original…
Powerwall v2 promises to really shift the landscape, offering twice the capacity of my unit, for roughly the same price. Other manufacturers are going to need to start offering more capacity or other desirable features to keep up.
Along with the big battery moves, 2017 looks like its going to be a very interesting year. Most predicted we wouldn’t hit this stage until 2020, but here we are!
Many jobs, with new types of infrastructure projects, will be required to make this happen. That means opportunities for people to jump on the train as its leaving the station.
Note: I’m always open to proposals in this regard.
Looking at my statistics, the last 28 days have seen generation below 21kWh / day, compared to a lifetime average of a little over 23kWh / day.
Consumption is also down, which is in part due to tapering off the pool pump now we’re in the cooler months.
Import is sitting around the average, though I haven’t needed the grid too much. The occasional Reposit Power off-peak import has bumped this number up a little, but I’m thankful for saving a few dollars.
Now that its been a year, with statistics, I’m satisfied that things will just tick along without my intervention. I don’t really have time to watch it 24/7 anyway!
I’ve started overriding my obsession with checking the system every 10 minutes.
As we sit here in a rare Sydney heatwave, I decided to blog. Its all I have the energy for.
Temperatures today are predicted to reach 46oC today. That is 115oF for those of you with funny thermometers. Sydney is supposed to hit a record February day, in fact.
As the temperatures rise, the standard position for most people is to turn on their air conditioner and shut all the windows. And that is great; electricity can often be the most efficient way to cool space.
The problem is the load it puts on the grid, and the possibility of blackouts in many areas, as people ramp up power usage in heatwave conditions.
The kicker: Australia has more than enough generation capacity to cover its needs. This overcapacity is only useful when the market operates correctly though, as this video shows.
* That is a really good article by Lenore Taylor above. Stop and read it. Give her a follow.
The good news is: consumers can help save it.
Combating the Heatwave
Normally you’d expect me to go on a rant here about Reposit Power and how microgrids are going to save the world.
The problem is that we’re continuing to consume high amounts of electricity to keep comfortable. If the heatwave conditions continue due to climate change, consuming even more won’t help – it will just make us hotter!
We’re stuck with fossil fuels for now, even while renewable technologies like solar, wind, and storage ramp up. In Australia at least, they’re going to be the majority of power sources until at 2025. Maybe longer.
As we’ve seen from The Guardian video above, the market can be “gamed” by generators, to help drive prices up. Even if you got a million Reposit Power boxes controlling 10MWh of storage, you’re not going to redress a balance of GIGA watts.
Part of the solution has to be a way to use less power. Therefore, instead of microgrids saving the world, I’m going to talk about something far simpler. Many countries in the world already practice it, but for many and varied reasons, Australia doesn’t.
Its a topic that is not nearly as sexy as GridCredits, but in Australia, its probably more important than ever. Let’s start with a quick diagram:
While that is a gross simplification, the basic truth is there:
Inefficient houses are built a lot here (and at high density)
They need more power to keep themselves cool or warm
This needs more power from (majority) fossil fuels
That makes more profit for electricity companies*
* It should also be noted that it means more (moar) profits for home builders, because the materials for less-efficient houses are correspondingly cheaper.
Its a vicious cycle, and its particularly ridiculous in places like Sydney where land is expensive to buy but houses are cheap to build. And once they’re built, they grow in value (but not efficiency) almost overnight.
I understand this because I bought a house three years ago and watched it increase in price 25% in that time. And it isn’t any more efficient today than it was the day I got it.
Except the pool pump I replaced, but that is another (angry) story.
Consumers Will Consume
Nobody wants to spend any more money than they have to on building their home. I dig that.
I lived in a house with two reverse-cycle split A/C systems for years, and always wish I had ducted.
When I got my new house, it had ducted. And the electricity bills were much bigger. But I didn’t put all of that down to the A/C – it was part of the issue, sure, but I had a bigger house with a few more TVs. Yeah, that must be it.
Now that I have the data on what it costs to run, I’m appalled, and looking for alternatives.
The first part was solar PV and a battery system. That has helped slice my electricity bill into tiny little pieces (blog coming soon on that).
To take it to the next step, I’m going to look at making my house more efficient. As I wrote back in March 2016, there are weak points in my house that need looking at.
Those windows on the west side of the house are next on the list, and I’m getting quotes for double-glazing and glass film technologies as we speak.
Advice For The Home Builder
If you’re building a home at the moment – or even renovating – I’ve got some advice for you, on how you can help with this heatwave situation. This covers both your personal comfort levels, and your contribution to the environment.
Look into designing your house right. Make sure you’ve got decent eaves. Windows that aren’t monstrously oversized. Understand the quality of the wall and ceiling insulation and MAKE SURE it covers the garage; many builders don’t insulate the garage, so its a massive heat collector, and can radiate through internal walls.
DOUBLE-GLAZING. Adds to the initial cost of construction, but will reduce your energy costs by 25-50% depending on aspect.
Get the Air Conditioner you NEED. Don’t just get the biggest one or look at the cheapest price. With the weather warming in Australia, you need to be sure that your A/C is smart. Make sure it is an inverter, and don’t worry about the slightly higher initial cost. It will pay for itself in efficiency measures, while electricity prices continue to rise.
If you find its not enough, then installing a small split system in a particularly bad area of the house can be done later. If you buy the big unit, you’re stuck with it for good.
Also, don’t be that guy who sets it to 21C appropriate. Your house should never really need to go below about 25C to stay comfortable if the thermostat is set up correctly, in the right location. This will save you thousands in electricity costs over the lifetime of the system.
Use ceiling fans and portable fans tactically, to keep air moving around your house. This is also part of using the 25C rule. If the air is moving, it often feels cooler, and the cost to run one is minimal.
The last measure you can do is speak to your local member about raising building efficiency standards in Australia.
At least it wasn’t peak pricing that day, being a weekend… Small mercies.
In addition to the anniversary, I’m also due to receive a bill from Diamond Energy, which will cover November through to January.
Putting in a guess right now: I’m going to say about $1.20 a day, excluding referrals. Similar to Winter, but with a bit of a discount for better export. That would be a bill of around $110 for the 92 day period.
Summer has definitely had an affect on the system, in terms of import requirements. As I mused back in December, summer would require more import, despite having more sunshine to work with.
Part of the reason is electricity consumption; on the whole, I am using more energy due to cooling and things like the pool pump.
The air conditioner is variable, depending on ambient temperature, and required comfort level. Short of replacing the thing, I’m stuck with needing the grid during summer.
How you handle your pool pump usage is up to individual circumstance. My pump has a flow rating of approximately 19,000 Litres per hour, and a pool of 31,000L capacity. I have a cover on it all winter, except for monthly maintenance, and no trees or other debris issues around the pool itself.
Therefore, in winter I’ll run it for around 90 minutes per day which should turn the capacity over about once. With appropriate chemical balancing, that keeps it clean.
In summer, I’ll vary it a little. During summer peak – where we use it a lot – the run will be 6 hours, timed for peak sun. At shoulder times I’ll start to move toward 4 hours, as we’re not using it as much.
The idea is to let the filter work as hard as it needs to, while retaining good chemistry and clarity in the pool.
Capacity and Usability
Happy to report that the Powerwall is still reporting its full 6.4kWh capacity, same as Day 1 of the system.
The extreme heat over summer also didn’t trouble the liquid-cooled unit. The Powerwall is rated to 50oC, unlike many of its competitors, so even an Australian summer can’t dent it.
Unless you’re crazy enough to put the thing outside. In the sun.
What I did notice was the rest of the system struggling to get to full capacity. With a total of 6.5kW of panels on the house, I didn’t always reach the 5kW capacity of the inverter.
Part of that is the panels getting hotter than their efficiency peak of 250C, and part of it is the inverter starting to feel a bit of heat stroke. Even in the shade, on the south side of my house, it gets bleeping warm.
Back in October I was hitting some sweet numbers, but the ambient temperatures were down in that 25 degree range. Everything performs better when its cool.
As the year has worn on, I’ve slowly weaned myself off frantic chart analysis. Its a bit of a pragmatic move, as constantly worrying about my ROI was a bit stressful.
While it was important to keep an eye on the system, I’m moving into a stage where I need to look at the future path, not just the past performance.
That means I’ll be presenting more ideas-based blog here, and there is plenty to write about.
Tesla Energy released the Powerwall 2, which I’ve avoided talking about due to extreme jealousy and consumer cognitive dissonance.
Accompanying that is solar rooftop, which I’ll talk about in a future post.
World-shaping events like Brexit and the election of Donald Trump are key political events. They have the potential to shape energy policy for years to come.
There are also ideas I’d like to explore in terms of other energy sources. That will lead into producing educational content that I can distribute, through various media.
I’m also aiming to put up more on my YouTube channel, for which I’d appreciate a “Subscribe” if you’re so inclined. Which I’ll try to fit in around the blog itself, work, family, and running a Rugby Club!
It has been a very interesting journey to get here. It wouldn’t be possible without the generosity of time and patience of the following organisations:
As scientific bodies continue to explore and model the effects of climate change, the technologists, disruptors, and entrepreneurs are seeking ways to combat it. The use of renewable power in the form of wind and solar is one of the key areas.
However, a valid criticism of renewable energy is stability: if the sun doesn’t shine, and the wind doesn’t blow, solar and wind are in under-supply. If the sun DOES shine brightly and the wind picks up, the renewable energy grid produces oversupply.
This situation is prominent in the California “Duck Curve”. The belly of the duck is over-generation from solar, while the head of the duck is the consumption ramp for night-time domestic use.
As domestic and commercial solar uptake increases across the world, there is a genuine risk to existing grids. Trying to address this issue alongside a mix of traditional power generation is difficult. Large, traditional generators cannot uplift generation, or halt it, at short notice.
I believe the natural solution is widespread adoption of storage technology.
Domestic storage will mature rapidly over the next 5 years, as household battery options become cheaper, due to vertical integration of the production process. This will be particularly true in established Western housing markets, particularly those dwellings with rooftop solar options.
It also enables the concept of virtual power plants for retailers to access power stored in domestic appliances. In the future, consumers will engage in peer-to-peer trading via blockchain and other smart technologies. The net result is to lower the need for a traditional “grid” and the associated maintenance for poles and wires.
Industrial storage will see positive disruption to hi-tech engineering solutions, using renewable generation. Efficiency has a large role to play here, as innovation across multiple sectors leads to better production engineering.
The volatility of frequency required for running many heavy industries can be offset with larger scale storage. These battery systems act like a buffer, or regulator, in order to provide assurance of stability. Large storage can also be deployed by energy networks in order to back up local power infrastructure.
Transport storage is a key area for addressing carbon emissions. While cars are the major playground for this technology right now, the move to heavy transport, agriculture, and public transport offers a range of other benefits.
I call it “Transport storage” because it offers more than just a way to move people or goods from one place to another. There is the opportunity to place domestic, industrial, and transport storage in synch, to produce a more efficient outcome for renewable energy.
Consider the California Duck Curve I mentioned before. This is the result of “too much of a good thing” when we have an over-abundance of solar PV! What if there was a way to mitigate this?
The average shopping mall in most countries has a roof space in the hundreds of square metres. They also contain hundreds, if not thousands, of car spaces.
If we add solar panels on that roof space, and storage in the basement, we can effectively create a curve smoothing apparatus by plugging in a suitable number of EVs during daylight hours. A similar system could be used by places of work for the benefit of employees.
Such a system would draw not only from the local (mall rooftop) power, but also spill excess renewable energy into recharging the transport network in other places. This might take the form of powering connected public transport – like electric buses or trains – on site, or via the grid.
All the while, this large-scale storage and renewable generation helps flatten the belly of the duck during the day. When people return to their homes at night, they can cut the head off the duck using their domestic storage.
Storage, along with the associated smart management technologies, provides the cornerstone for a renewable energy future. The combination of increased efficiency, and reduction of fossil fuel burning, is undeniable.
They looked at the system, and advised placing an extra six panels on the western roof. The same Phono Solar 250W panels would be used, each with a SolarEdge P300 power optimiser.
The two existing arrays tie back to the inverter with one string each. The new array would be joined onto the array to the left of picture (western). This made for the simplest install as it didn’t require new wiring to the inverter.
It also provided the benefit of generating from the sun in the afternoon. This is useful in the warmer months where I am more likely to use air conditioning.
Additionally, for those days that have overcast mornings, but sunny afternoons, I’d see the most benefit. Particularly true given the house has a rising ridge line to the east, so doesn’t see much sun early in the day.
With the detail sorted out, we agreed on a date for Splice Electrical to perform the upgrade. James and Nick turned up, and with their usual friendly professionalism, got to it.
While they were here I also got them to disconnect some old PSTN infrastructure that was slowing my NBN connection. Increased speed by 40%! Legends…
A few hours later I was the proud owner of another 1.5kW of panels!
Naturally, with an upgrade of this sort, you’re going to expect some improved results. The system has had a size increase of 30% (1.5 / 5.0 = 0.3). Would I get similar generation increases?
The main factor in all this is still the inverter. The SE5000 in my system is limited to 5kW in any direction. Therefore, expected generation, even with 6.5kW of panels, is limited to 5kW maximum.
I was quietly confident I’d hit this high mark regularly, given I generated 4.9kW or more at points during February and March, and even in May!
However, the panels aren’t in the same orientation as the rest of the system, so what is the effect?
Setting the baseline
According to one source, a solar PV system in Sydney should produce 3.9kWh per kW of installed panels per day. That is under lab conditions.
My initial system setup should (on average) have produced about 19.5kWh of electricity per day. For the lifetime of the system at 5kW, the SolarEdge API reports the following figure:
I hasten to point out that the data is a little murky. The SolarEdge API consolidates “generation” from PV and battery, because of the way it monitors flow.
Therefore, that figure only works if we’re assuming the battery is filled and drained every day. This certainly isn’t the case 100% of the time, but its enough to show we’re in the ballpark.
Another part of this is loss due to inefficiency. The Powerwall is about 92% efficient, meaning I have to spend around 1.5kWh of the 19.5kWh figure on the power going into and out of the battery.
The other factor is the timeline; we’re looking at a period from mid-February to early October. This includes the shorter daylight hours.
With all these factors considered, I’d say this is actually looking like a decent marker, even with the accepted error margin (+/- 10%) in the SolarEdge API.
Effect Of Upgrade
An extra 1.5kW of panels should result in a generation figure of 25.35kWh per day, on average, for Sydney.
The first caveat for this figure: it has been spankingly good weather in Sydney for the last week.
The new panels are also a different orientation to the others, which may affect the figure.
It is also a very small sample in terms of days. In the interests of science, I’ll leave this chart here to update daily. You can check in on it any time you like. A rolling 7- and 28-day chart is also on the Statistics page.
Average just shy of 33kWh at time of print. Pretty good weather!
A better analysis might be to look at the curves being produced by the different panel setups. The figures aren’t as important as the shape of the curve.
A small point: that is my record day so far. And its only October. Tee hee!
More importantly, we see the extension of the curve from the new peak around 1PM (daylight savings, remember), through until the late afternoon. We get a lot closer to sunset for generation as well.
The peak 5kW on this particular day hit at 1128 hours, and it stayed there until 1514 hours. The 5kW system infrequently reached 4.9kW, and then only for short stretches.
With the extra panels, not only is the generation figure much higher, but the long afternoon sun really kicks in.
As we move further into the warmer months, I expect the 5kW peak to be longer. Most likely, this will result in much more export until the point the ducted air conditioner is required on a regular basis.
I need to develop a strategy to mitigate that. Perhaps running the air conditioner in “continuous” mode on sunny days will help. This aims to keep the house cool, and the thermostat will lower the overall energy requirement.
I’m still finalising the change in payback time on the new array. Due to the move to TOU pricing, it is getting hard to keep all the facts and figures in order.
For the most part, I’m going to keep rolling calculations based on the single-rate plan offered by Diamond Energy. The rest of it makes my head hurt.
I’ve had the Powerwall six months now, or in fact a little longer. It would be more accurate to say I’ve had a functioning solar PV with battery system for seven months.
That dates back to when my meter was changed over to a basic bi-directional unit. Importantly, it is the date that billing with Diamond Energy started, with full and accurate detail of import and export.
I have had a total of three bills, the most recent of which covers 52 days from mid-June to early August. It stops there because I’ve moved from single-rate to TOU tariffs, so Diamond decided to make things easier for calculation purposes.
The other two were covered by my blog post back in July. The full quarterly bill naturally received more attention than the one I hinted at in that post. With 174 days of billing data now in the bank, its time to look at a longer period.
This post will put up the basically points of interest from the three bills and their relevant statistics.
Powerwall Six Months Analysis – Part 1
The first bill covered the period of 17th February through to 23rd March.
Average / day
* This amount removes the $20 establishment fee with Diamond ($22 inc GST)
With a connection fee of just over $0.82 / day, and an export tariff of 8 cents/kWh, I was almost covering the connection.
Of course, import was going to hit a bit harder in summer time. The last week of February was a record-setter in Sydney.
The temperature was minimum 26oC / 79oF for nearly the whole week. Frequently the temperature was over 35oC (95oF) in the late afternoon, hitting those big, west-facing windows. I can only sweat so much!
That kind of heat requires air conditioning, which you can see in the red spikes below.
It probably wasn’t even the amount I imported, more a case of when it was imported.
This is a small precursor to what you can expect from an Australian summer in this part of Sydney region. No ocean breezes this far inland.
During this period I clocked some fairly hefty production figures, topping out at around 34kWh, with several days in excess of 30.
The heat of a Sydney summer makes me a little cautious in regard to power usage. In addition to the extended hours for the pool, the heat will require air conditioning. That means import.
January tends to be the wettest month in Sydney, and storm season. Luckily, for those cloudy days and weeks I’ve got Reposit Power to do the thinking for me.
POWERWALL SIX MONTHS ANALYSIS – PART 2
The start date was 24th March, running through until 17th of June, 2016. This was the big quarterly bill which grabbed the media attention here in Australia, with a few overseas articles published as well.
As you can see, the daily figures show slight decreases across the board.
At my import tariff, this equates to 13.2 cents / day decrease in costs as I’m importing less.
The export is 4.8 cents / day cost increase as I’m exporting less.
This comes out to 8.4 cents per day. The actual decrease of 9 cents per day is due in part to rounding.
Additionally, Diamond single-rate tariffs step up by a small amount once you use more than a certain number of kWh per month.
The weather during this period was pretty good. We had long weeks of sunshine, with few rainy days. The temperatures were very mild, meaning we didn’t need air conditioning or heating.
POWERWALL SIX MONTHS ANALYSIS – PART 3
The latest bill runs from 18th June through to 9th August, or a total of 52 days over winter.
In terms of “winter”, I should mention it never snows here. The closest snow I think fell about an hour’s drive away, in the Blue Mountains. It isn’t frosbite territory, and with the climate warming, isn’t ever likely to be. Short of another ice age, I guess.
We do get frosts, sometimes on consecutive days, and the lack of double-glazing, with basic wall and ceiling insulation batts, does mean the house gets cold. We also have a lot of tiled floor.
This bill gives a valuable insight into the changes that occur, in a period with less sun and more heating.
Average / day
A little over double for daily cost, and the reasons why are fairly obvious.
Import rose by 91%, and export fell by nearly 27%. So it cost me an extra 50 cents per day for import and I missed out on around 18 cents for export. In the ballpark at 68 cents.
There were only a couple of days where we ran the heating longer than an hour or so. With the big motor on this ducted system, that was more than enough to start hitting the import hard.
Next winter, with TOU now in place, we’ll be a bit smarter. I’m talking to Reposit about the best ways to utilise off-peak power, and how their software handles it.
Note: the reason behind the short interval for this bill is replacement of my meter. The GridCredits scheme is reliant on a sophisticated unit, which I’ll put up video of when I get the time.
Putting all the information into a table gives a nice summary of the solar with Powerwall six months down the track.
Not bad, though of course I have yet to experience a full summer with this system.
Summer will mean more power imports as we use the air conditioning. It also means longer daylight hours. Greater export will offset higher import, to a degree.
Compared to winter, where heating and shorter daylight hours have clearly had an effect, summer should be slightly better. I’m still at the mercy of those 40oC+ days, but at least I can pay them back a bit.
Of course, as panel temperatures rise above 25oC, efficiency will drop. More light = more heat in summer, so I might not see many days above 35kWh with the existing system.
Autumn and Spring are looking like the “Kill Bill” (*snigger*) periods for the year. The milder weather and lower heating/cooling requirements are really where its at.
Winter is going to be an issue ongoing, with lower daylight hours, and heating requirements. Summer will still need a lot of electricity imported, but can be offset with big exports.
The real challenge, moving forward, is to maximise self-consumption, and minimise waste. As always.
If I can keep the costs below $1 / day for my electricity, even with recent increases in tariffs, then I’m well on track to save $1900 in the first year. Maybe more after that!
It has been a hectic couple of weeks, after the release of my first quarterly power bill. I’ve been on radio, TV, in print, and sprayed around the internet. Its a bit like the install day back in January, but obviously with a dollar figure attached.
Despite that, there is still a lot of people ready to step up and put the boot into Powerwall, and lithium storage in general. I will never fathom why these parties are against progress, so I don’t read into it too much.
BUT ENOUGH ABOUT THAT…
During that time the world rolled on, and it appears renewable energy, particularly solar hybrid, has been going from strength to strength. One tweet in particular caught my eye, from Noah Smith.
2010: "Solar will never be viable without subsidies!" 2013: "Solar will never be viable without storage!" 2016: https://t.co/LHvPC2IVyw
The Telegraph article linked by that tweet, written by Ambrose Evans-Pritchard, is an interesting discussion on battery storage as it affects the landscape. It is also a bit of a dig at the Hinkley Point nuclear project in England.
I wrote something previously on Nuclear Power, so without a re-hash I will reiterate: I AM NOT ANTI-NUCLEAR. However, I did point out there are significant financial hurdles to overcome in Australia. Leaving aside the social issues, that is.
Three paragraphs in the article from Evans-Pritchard got me thinking.
Perhaps the Hinkley project still made sense in 2013 before the collapse in global energy prices and before the latest leap forward in renewable technology. It is madness today.
The latest report by the National Audit Office shows that the estimated subsidy for these two reactors has already jumped from £6bn to near £30bn. Hinkley Point locks Britain into a strike price of £92.50 per megawatt hour – adjusted for inflation, already £97 – and that is guaranteed for 35 years.
That is double the current market price of electricity. The NAO’s figures show that solar will be nearer £60 per megawatt hour by 2025. Dong Energy has already agreed to an offshore wind contract in Holland at less than £75.
Those are some pretty compelling numbers, but the reasons why it got me thinking relate to my own work life.
A Short History Of Dwarves
I’ve been an IT guy for a living nearly 20 years now, working mainly in databases where I can help it. I’ve seen almost every tech acronym or buzzword put into practice, sometimes very poorly. Or for the sake of change.
One of the better periods was back in the day, when the technical stuff was held apart. I like the imagery that Neal Stephenson uses in Cryptonomicon – IT guys were like the Dwarves in Tolkein; working away in the dark, hammering out things of beauty like Rings of Power.
The company (Elves) would frolic up to the entrance of the forge, beseeching the Dwarves for a solution. The Dwarves would give a range of timelines and costs, and the Elves would pick one. We’d go into the forge, create what they wanted, and the land was content.
With advances in technology, and the hunger for globalisation, things needed to move faster. Thus, “Agile” was born as the new way to do things.
Generally speaking, the move to Agile is positive from my point of view. It seeks to guide the Good Ship Project through the icebergs as each one appears, not assert a course from Day 1 and expect no issues with implementation at all.
As long as Agile is implemented the right way, it can do good things.
There is a caveat though, and the seed of this started with smart devices in my opinion. If we’re ever having a beer, talking shop, I’d pinpoint smart devices as disruptive in more than just a good way.
Now non-technical people see an awesome app for $1.99 and wonder why projects still cost millions. As a result, they demand more.
Agile has collided with this belief that speed of delivery, and convenience, is cheap. Non-technical people don’t necessarily understand the systems. They’re trying to tell the developer how to do their job down to the finest detail. That isn’t actually helpful.
Dear Managers: right now, there IT guys reading this, and nodding their heads. Maybe muttering. Likely, swear words and dark thoughts are being countenanced.
Agile Energy Projects
One thing that holds true of IT projects, energy infrastructure, and pretty much anything down to a backyard deck, is the Quality Triangle.
If you are going to implement or change the project in terms of finances, timeline, or scope/size, then you have to accept it will affect the quality of the outcome. Aiming for all three is purely theoretical, in my opinion.
As with the recent Census Fail incident in Australia, sometimes it doesn’t matter how many resources you throw at a project, or how long it runs. The excreta hits the rotary ventilator, and its time to put out fires.
Hinkley Point C is subject to some base requirements, but the main one is the generation of 3200 MWe from a nuclear reactor. Not the biggest in the world but still a mighty undertaking.
Once you’ve decided it will generate that much, you’ve set your course. A prescribed amount of effort, human resources, and other elements must go into it. Critically, the reactors will be of a certain size and type, and you’ll pay the capital cost of that regardless.
If you encounter cost overruns or other issues, generally speaking you just have to suck it up, as per the article:
… the estimated subsidy for these two reactors has already jumped from £6bn to near £30bn. Hinkley Point locks Britain into a strike price of £92.50 per megawatt hour – adjusted for inflation, already £97 – and that is guaranteed for 35 years.
In Australian terms, that is $160 / MWh, which is frankly ridiculous.
All of this points to the fault lines emerging in “baseload” power argument. Not only is “base” power a myth, but the agility of these big power generation units is practically nonexistent from conception through to decommission.
As Hinkley Point C, and Finland’s Olkiluoto construction debacles show, centralised nuclear power might be green, but it isn’t necessarily going to stand the test of time, economically.
Smart Advantage of Renewables
Technologies I have seen work, or worked with directly (like Reposit Power) show us that agility is the biggest factor in any tech marketplace today.
And let’s not kid ourselves: energy delivery is now a technology field. This is particularly true of renewable energy, which eschews the old school sledgehammer approach to power generation, in favour of smarts.
Smart use of power, smart direction of power, are going to be the big players moving forward. It starts with domestic applications, such as Tesla Powerwall, and smart management to deliver benefits for the home owner.
Beyond serving one household, it has the potential (and in some ways, the obligation), to serve the wider community.
This is achieved by using the battery as a trading platform. Benefits abound for the network willing to engage with customers, as I discussed in May. Reduced overall costs and waste benefit everyone in the longer term.
This move toward smarter storage also helps address the business sector. The power needs there are large, and despite being mainly during the day, will not going to tolerate the intermittent fluctuations of solar PV and wind.
Storage using batteries is one leg of the argument, across a various range of chemical makeups. Energy storage like pumped hydro can also assist deliver stable power on a larger scale. The big one for Australia should probably be molten salt reactors, particularly for South Australia, which has suffered issues recently.
Certain industries have scope for change today. Heavy transport, and transport in general, is already under the microscope in nations like Sweden, where they seek further reduction in carbon emissions.
Electric Vehicles take carbon off our roads and out of the manufacturing process through a simpler template of construction. If you don’t believe that, think about the amount of metal required to build a drive train for a petrol engine, versus an EV’s battery & motors setup.
How do we address the remaining heavy industry players, and areas outside domestic power supply that aren’t easily converted to renewable technologies?
Scale Advantage of Renewables
Critics of renewable energy sources often derisively quote land area required for building large-scale generation. Regardless of whether its wind, solar PV, pumped hydro, molten salt, or another method, a “farm” for renewable power will take space, that is true.
Renewable energy projects are much simpler to implement from an engineering point of view, compared to a nuclear reactor. They are also more flexible.
A nuclear plant, once scoped, has very little opportunity for changing the Quality Triangle. It also isn’t going to get much more efficient if you delay implementation, because the technology is largely static.
Manufacturing issue with your solar PV arrays? Let’s just get less panels for now. They’ll be cheaper later on, or more efficient, anyway.
Dispute over one of your wind turbines? Fine: proceed with the rest of the farm until the outcome is known.
These are two examples (there are more) where the scalability of renewable energy creates a huge advantage. The unit size of a wind turbine, or a solar array, is in no way limiting for people who know how to implement them.
Pumped hydro and molten salt reactors are similar to traditional power stations, in that their capacity is roughly determined at time of construction. The key difference is they are primarily storage, over and above being generation.
They don’t need to be on all the time, only engaged when other resources are running low, or as demand spikes. This is another advantage over “baseload” coal or nuclear, which cannot uplift to address demand spiking.
Only gas-fired stations have this ability at the moment. The surging price for gas, as well as its status as a fossil fuel, renders it a short-term option at best.
The Paradigm Shift
You cannot simply build a traditional network and throw more and more renewables at it until you reach a very high number.
Coal in Australia has been built to over-capacity, resulting in wasted capital expenditure, and poorly managed outcomes. Witness the issues South Australia has at the moment, because of short-term thinking around renewable energy integration.
We need “smart” implementation of renewable energy projects. Flexibility must remain a core tenet of implementing this intelligence.
As Evans-Pritchard covers in his article, there are many storage options in development across the world right now. We’re in a period of real transition where more options will blow the marketplace right open.
This requires the right thinking, to engage renewable sources on a far larger scale, holding hands with storage options of all kinds. Markets will shift rapidly. Consumer needs, particularly in the developing world, will have no need, and no money, for sledgehammer tactics like “baseload” power.
Projects designed for even 30-year life cycles will find themselves at risk of rejection. It will be simply uneconomical to support such inflexible systems.
With the right people at the wheel, concerns over our energy needs, and the perceived shortcomings of renewable energy, needn’t be a concern.
As I’ve been hinting for a while, the first bill has landed – Billing Awesomeness Powerwall Style! The guys at Natural Solar and I have been jumping out of our skins to get this moving, but all good things in time.
I’d better come clean – technically this isn’t the “first” bill. I actually got one over a month ago, which only covered 35 days due to various scheduling issues with the meter changeover and reading.
And don’t get me wrong: that 35 days was a very small amount, particularly as my last summer bill was $660 (!!!), but I felt it best to wait and see.
Now that we have a quarterly amount, which also lines up roughly with the same billing period last year, I (and everyone watching) can compare apples more easily to apples.
Let’s go to the numbers, courtesy of my poor quality photography. Here is the bill from the “Autumn” quarter last year:
Of course, I’m a fine and upstanding citizen (stop giggling), so I paid on time to get the appropriate discount under my plan.
And here is the bill from “Autumn” quarter this year – this amount also includes the pay-on-time and direct debit discounts:
Ninety per-freaking-cent reduction!
Not too shabby, but as always, it isn’t the whole story.
The 2015 bill overlaps the 2016 period by a few days at each end, so this is only a fair comparison if we look at the number of days on each bill. Hey let’s do that to FOUR decimal places!
$ / Day
So… yeah… that’s 59 cents per day for electricity. And if you recall my ROI/payback article from April, you’ll know that under Diamond Energy single rate plan I pay a tick over 82 cents per day for connection, so I’ve even reduced the connection fee by a fair whack.
That makes it pretty clear that I was smashing out the solar power with extreme prejudice from my 5kW array. The final number was a tick over 3 kWh exported for every 1 imported. Always going to look good when you’re getting 8 cents for export, from the legends at Diamond Energy.
I will throw in here: that bill doesn’t contain a single GridCredit sale, either. Nor does it contain any off-peak (TOU) power. That is pure, single-rate, import versus export.
And I think I could do better, but we’ll get to why that is later.
Billing Awesomeness Powerwall Style – Factors
I suppose it was a pretty mild weather period, but then in Sydney for the Autumn period that’s not unexpected.
Looking at the energy consumed per day is also helpful:
kWh / Day
Note that because I don’t see how much I consume on the bill, I’m having to use the data generated by the SolarEdge API. In my experience so far it is fairly accurate, though it has a small degree of variance due to updating on the quarter-hour, as I understand it.
A good reduction in usage, due in part to having a couple of new devices we needed to replace, like the oven. The old one was listing badly to port, in naval terms.
That reduction is also about learning my consumption patterns via the SolarEdge and Reposit Power portals, and coming up with the best way to eliminate waste.
I’m also paying a bit less for my power overall since changing providers, but as I’m only importing around 3kWh per day, that is of negligible effect on terms of cents per day. The connection fee is only a tiny percentage different.
Critics will be quick to jump in at this point, with smugness, clamouring that its NOT just the Powerwall.
While that is a fair point, at the same time, they should not be dismissive of the lessons the system has taught me.
To digress into simile for a moment: I went to University, and it cost me a lot of money, but it didn’t get me a job; it gave me a mindset, problem solving skills, and the experience of those who were my educators.
Likewise, I have not just purchased a battery, but an entire solar PV system with smarts. With it, I have been given the opportunity to generate, store, and export that energy. I can access new energy trading markets such as GridCredits.
Most importantly, I have a new way of thinking, evidence to track my progress, and help from a range of people across the industries involved.
The battery, by itself, doesn’t deliver miracles, not was it ever intended to. I’ve made it very clear from early on that there were tangible benefits to the Powerwall.
The power shifting aspect of the battery is extremely important to reducing my import requirements. I don’t get Gross Tariffs, so moving what I can to the daytime is great.
BUT we don’t get to spend our whole day at home (the kids would drive me up the wall), so there needs to be other ways to reduce or offset that cost. That’s where the Powerwall takes over.
The ROI blogs I’ve written state quite clearly that any household could save money by making simple changes. Smarter devices. Better practices. Maybe a new billing provider. It didn’t matter whether they had even had solar PV, much less a battery.
A household with Solar PV on Net Tariffs has probably learned some of these lessons already. For them, the cost of a battery is a marginal prospect today but is certainly on the radar.
A household with Solar PV and Gross Tariffs in NSW is probably looking for “what next” as they lose those benefits at the end of the year. Perhaps they haven’t had to think about these factors, but they probably will (and I know some who are), once they start actually importing power at a cost ratio which reverses Gross Tariff costs.
I just look at the FACTS: I’m saving about 90% on my power bills. I’m making my household greener than it was, through waste reduction and buying green power. I’ve been asked to relate my experiences at conferences, schools, and work places.
People are interested in this technology, and want to see it in action before they commit. Hopefully this kind of real-world data, even if its only one site, will help.
As a side note, based on this one bill, the return is in the order of 10%. Extrapolating that, factoring degradation versus increase in power costs, the 10 year window on my warranty is looking pretty safe.
And I’m not done.
The next arrow out of the quiver is my upcoming move to time-of-use
billing. That way, I can start really getting the most out of the Reposit Power software to drive those costs down even further.