In the market for solar power? Don't fall for these tricks

To figure out exactly what you should be looking for – and any pitfalls to avoid – we played around with the software many solar panel companies use, to see how easy it was to make it look like you're getting a better deal than you really are.

The software we used is called Open Solar. It’s designed for companies to generate quotes for potential customers. Luckily, it’s free and you can set up your own account to have a play. We created our very own Consumer NZ solar company on Open Solar and started generating quotes.

How solar panels are sold

The art of selling solar panels comes down to making them seem financially viable. The company needs to convince you, the homeowner, that panels will work and are worthwhile, by crunching the numbers and making them look attractive.

How Open Solar works

The program lets you set up an account to design systems for potential clients. It’s actually quite fun to use. Designing a system is as easy as clicking the mouse and dragging panels across the roof of the property you’re designing it for, using images from sources including Google Maps and Toitū Te Whenua – Land Information NZ.

From there you can refine the specific solar hardware down to brand and model. You can also input the energy information for the house, including the usage and price the occupants pay for power.

The program spits out a very polished-looking proposal for your customer, which can be customised further to suit your brand.

The problems with Open Solar: what we found

Any industry, be it big or small, can have a dodgy element to it. Consumer NZ Solar got off to a shady start when we learned how to fudge the numbers.

Unfortunately, the chief salesperson (me) developed a crooked streak and soon learned how to deliver bogus numbers that paint solar in a better light. It turns out that it’s quite easy to make solar look incredibly attractive to any potential customer, if you know which buttons to press.

Here’s an example of a normal projected electricity savings graph versus the one with the fudged numbers. This is using my house as an example. It’s a place with modest electricity usage where nobody is home during the day to use power – apart from the cat, which doesn’t ever run the dishwasher.

Realistic savings when adding solar

Dodgy savings when adding solar

You’d never see this sort of impact on my monthly bill with a regular system that doesn’t use much power during the day or has batteries. If things are dropping by up to a half on a quote you receive, ask questions.

We set up two identical systems here, on the same house, for the same price. There’s one massive difference though. We messed with the amount of generated electricity that is used by the household.

In a normal setting, most of the electricity that a household’s system generates is exported to the national grid. That’s unless you spend your days at home using power when the sun shines or appliances are actively managed to turn on in the middle of the day.

The default settings on Open Solar take this into account.

However, by fiddling with the advanced settings, Consumer Solar’s honest quote was set to the standard self-consumption rate while the rather dodgy one was set to 100% self-consumption.

This change doesn’t show up anywhere on the final quote sent to the customer. It just has a major impact on the payback time for the system.

Normal payback takes nearly 15 years

Dodgy payback looks much better to a potential customer taking only 8.8 years

How to protect yourself

Arm yourself with knowledge beforehand. If things seem too good to be true, they probably are. The sage advice for anyone looking at getting anything that’s expensive and bolted to your house is to get multiple quotes.

Ask questions

Ask about the numbers that any potential installer has fed into their software that’s used to generate a quote for you, to make sure things aren’t off.

Be sure to ask about the self-consumption rates too. If it doesn’t show up in your final quote, ask for evidence showing what rates were applied in the first place.

Be armed with the right information

If you have all the past 12 months of electricity bills, be sure to have them ready to go. The company providing the quote can put them into the energy usage section on Open Solar to generate the most accurate quote.

Do your own background work

Use the Gen Less calculator to get an idea of the payback times for any system you might have installed. Some pundits may bemoan the fact that the calculator is on the conservative side, but that’s much better than overstating your returns. It’s best to err on the side of caution and have these figures lined up that you can then compare to any quote you might be given.

We wouldn’t recommend that you use Open Solar yourself. It goes too deep into the weeds for a basic overview, and you can get quite carried away.

When are batteries going to save the day?

Unfortunately, the price of batteries hasn’t hit the basement like we had all hoped. The main reasons for this are increased demand from vehicle manufacturers and skyrocketing costs of the components to make them. Lithium is, unsurprisingly, the key ingredient in lithium-ion batteries and things are only trending one way.

We’ll keep an eye on things but for the time being, batteries remain a luxury rather than being financially viable for most grid-connected homes.