So You Want To Go Solar…

A few people – friends, friends of friends, complete strangers – have asked me what the best solar system to buy is. “How many solar panels?” or “Should I get a battery?” and “What is that thing growing out of your head?”.

To them I say:

Note: that totally isn’t me. Nor am I associated with (c) Snorg. But its funny, so click on it.

Everybody’s house is a little different. Everybody’s use case is a bit different. Solar isn’t just a cookie cutter approach; at least, not yet.

What I can say is that there are a few steps I’d recommend to anyone thinking about installing solar panels and/or a battery.

(Oh wait: I forgot the paragraph wailing about how slack I’ve been on the blog. That was it – well except to say I got a new job in November 2017 working in energy which is pretty rad, but keeps me way busy).

Motivation For Solar

People want solar for different reasons, and from my experience of the last two years, it breaks down into a few things.

Driving down electricity bills is usually numero uno, and there is nothing wrong with that. Investing thousands into something functional like a solar PV system, you’d want to see some payback and/or stick it to “The Man” if you’re angry about whatever it is “The Man” has done.

Green feelgood is another factor. Reducing your grid needs helps save operating costs on your house, as well as your carbon footprint. You also get to understand your ability to contribute to the energy ecosystem via renewable energy.

Curiosity is a relatively new thing, particularly for modern systems with API-driven inverters. Some people (me) like to watch what is happening on their solar system at various intervals, e.g.

After that, its a question of “Do you really *need* solar?”

Where To Start

First place is your electricity bill.

Look at the amount you consume on a daily basis across the year. Figure out whether there are major differences between summer, autumn, spring, and winter, and I’ll bet you start to see where the pain points are in terms of running certain devices in summer (AC) or winter (heating).

As I’ve said before: most of us get our bill, have a bit of a rage about it, and then pay it and move on. You need to take the time to analyse who you are, and what you use. It will be very helpful.

Have you spoken to your electricity provider about getting the best deal? Sometimes we pay too much via “lazy tax” where we can’t be bothered even making a phone call.

Have you told your electricity provider that you’re speaking to other electricity providers about the best deal? That can be quite the motivator.

Does your electricity provider offer “green” power options? That might elevate your bill slightly, but give you part of that feelgood factor you’re after.

Efficiency, Efficiency, Efficiency!

Next, I’m going to ask whether you’re doing everything you can to reduce your electricity consumption.

Energy Efficiency is a very much overlooked part of housing, particularly in warmer places like Australia. Building standards here aren’t so great compared to other parts of the world, and we compensate using air conditioners.

I have to say I’m guilty here of jumping into solar + storage before really checking why my bills were so high. The good news is, I’m addressing these issues now by getting awnings on my west-facing windows as well as installing downlight covers in the ceiling to reduce insulation gaps.

Perhaps it is something as simple as setting your thermostat too hot/cold, and trading money for a tiny bit of discomfort. In modern HVAC (Heating, Ventilation, Air Conditioning), each degree you set your AC up or down from 25oC can cost 10% more energy. Not cool. Or hot. Whatever.

Check all the gaps around your doors and windows. Deploy window coverings against the sun, or heavy curtains against the cold, wherever possible. Turn off the beer fridge if you’re not really using it. When you replace a device, look at the energy efficiency rating system (it can save you hundreds).

The possibilities are not endless, but they’re available, and significant.

The goal is to consume the minimum amount possible without making yourself too uncomfortable. And maybe a little discomfort isn’t such a bad thing 😉

Alright, so let’s say you’ve covered the energy efficiency thing, and have a fair handle on your bills. That’s half the battle. Let’s talk about solar.


Not every roof can handle a solar PV setup. I’ve lived in a house that could not, due to a lack of appropriate space.

Start by looking at your roof space on Google Maps, and see if you have north- or west-facing roof space that might host a decent array of panels, if you’re in in the Southern Hemisphere.  For those north of the equator, its south- or west-facing, obviously.

In some cases you might even want to have east-facing panels as well, due to your usage patterns. Morning people; they exist.

The more complex your roof layout, the more it is likely to cost for installation. Two storey installs can cost more in some cases. Single storey might get tricky if you’ve got multiple roof lines with minimal contiguous area.

Roofing material may also determine how difficult the install becomes, as different fixings and sealing methods are required.

If in any doubt, talk to a local installer. That’s where Google Reviews and recommendations can come in handy – find the right team and you’ll reap the benefits.

A Galaxy Of Solar Systems

The trouble with me recommending anything is that the internet will immediately have an opinion on it. You will read reviews that are negative about perfectly good solar PV equipment, maybe because an individual had a bad experience.

There are thousands of combinations of solar panels, inverters, and (if you require it) storage systems from which to choose. You’ve also got different metering options, which can affect how you get billed, and how you might leverage peak/offpeak power rates.

“How many panels do I get?” is a pertinent question, and my response is always that panels are cheap, so get as many as you can afford.

Remembering that in most new setups, you’re in a “net” situation i.e. the panels feed your house first, then sell any leftover energy back to the grid at a modest rate.

Trying to self-consume every last kWh you produce is a waste of time for a grid-connected system, in my opinion. You’ll end up with a smallish system that meets your needs generally, but you’ll miss a lot of the cost offset you get from feed in tariffs, and payback time will be no different, or longer.

Panels are cheap. Get as many as you can afford.

At the same time, get an inverter that will handle that load. Having 6kW of panels isn’t going to mean much if your inverter is designed for half that. I’ve got 6.5kW of panels and my inverter maxes out at 5kW, which is generally OK, but I’d like a bit more 😉

In Australia, I’d recommend a minimum of 5kW of panels. A system of that type will cost you around $6000-$7000 in Australia (installed). In the USA, Trumplandian authorities will ensure it continues to be about double that.

Adding A Battery

Adding storage can double (or more) the cost of a system pretty quickly.

At this point (February 2018) it will extend the payback time accordingly because lithium batteries are still coming out of the early adopter phase. It becomes a question of capital investment versus operating cost.

If you get only the solar panels, you can get payback in under 6 years.

This makes the assumption that you’re operating the system with a decent amount of thought. Move heavy loads to the middle of the day when the sun is shining and the panels are blazing. Make the most of your feed-in-tariffs, where available. Be aware of your efficiency issues, and address them.

If you do all this right, you could get payback down below 5 years, BUT you’ll still be paying an electricity bill, even if its smaller now.

Today, the battery option will take your payback up past 6 years again, and maybe as high as 8 depending on the specifics.

There is a benefit, though: your operating costs for electricity will be closer to zero than if you have solar alone. Heck, maybe you might even turn a small profit!

There are additional benefits to your battery install as well, if you have smart technology like Reposit Power attached to the system. Selling power for $1 / kWh a few times a year might not sound like much, but when your total bill is close to zero, its heading toward profit.

It can help you save money on electricity via arbitrage if you have the right metering setup. Reposit maintain a list of good installers to use in Australia, who will ensure you get the best result.

But How Much Will I Save???

Well, I can’t really answer that, unequivocally. A lot depends on individual circumstances.

I’m saving about $2000 per year over the first two years, having made small changes to how I run my house. I continue to make these changes as I explore ways to reduce my usage.

If you’re just going to whack the system in for something cool to look at, but not change any of your habits, expect your savings to match your behaviour.

P.S. if you want to move providers, and grab a $35 credit while getting a 12c feed-in-tariff, hit me up on Twitter for my Diamond Energy account number. They’re green, clean, and lean, as well as being partnered with Reposit for Grid Credits.

Heatwave Conditions Do Not Compute

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.

In a week where the Federal Government decided to use coal as a political football*, particularly on their support of coal over newer technologies, videos like this show how broken the system is.

* 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.

Energy Efficiency

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:

  1. Inefficient houses are built a lot here (and at high density)
  2. They need more power to keep themselves cool or warm
  3. This needs more power from (majority) fossil fuels
  4. 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.

Politically Speaking

The last measure you can do is speak to your local member about raising building efficiency standards in Australia.

I was fortunate enough to hear Dr Brian Motherway talk about efficiency at a conference last year. Efficiency is one of the key targets of the International Energy Agency.

Countries like China are ramping up policy and action in this area, as well as decreasing their reliance on fossil fuels in favour of renewables.

Those nations that don’t look at the entire energy spectrum are going to be left behind. And what is the point of pursuing a green grid if we’re still wasting it?

With that thought foremost in my mind, I’m going to jump in the pool with a beer.