Homeowner Blog

Image source: Optigreen.

Those looking to make the greatest benefit from their roof space may feel they should choose between solar panels and green roofs - but can you combine the two? Yes - though both systems need to be designed properly.

It’s important to do your research when planning your solar system, but the sea of technical terms can soon become overwhelming. Let’s address some of those you may come across when comparing types of solar panel - and see how those types stack up.

Why does the solar panel output matter?

When installing solar panels there are many things to deliberate over, whether that be the price or aesthetics, but probably the most important metric to consider is the output. More often than not the price you pay for an installation will be relative to the power output of the system. The rated power output or wattage of a panel represents the theoretical power output under ideal conditions and is a strong indication of the amount of electricity a panel will generate. However, there are factors other than the panel’s wattage to consider when determining its output or energy generation. 

The solar PV industry has faced a year of change in 2019, with more uncertainty lying ahead. First came the end of the Feed-in Tariff, the guaranteed payments for people generating solar energy. The 50% deemed Export Tariff for smaller systems ended at the same time and we’re still waiting to see what will fill the gap, to prevent customers with new solar systems from exporting excess electricity to the grid for free. (Don’t worry, this doesn’t impact people who installed their system before the final Feed-in Tariff deadline of 31st March 2019.) The current proposal from the government is the Smart Export Guarantee (SEG) - more on this below. As a final kick in the teeth to the industry, another threat to solar PV installation has resurfaced - a potential solar VAT rise on domestic systems from 5% to 20%.

So what does all this mean to you? Is solar PV still worth installing now, either as an extension to your existing system, or as a new system altogether, or should you wait? And what about a solar battery?

Around 30 GigaWatts of the UK’s older fossil fuel and nuclear capacity is due to be decommissioned by 2025. At the same time, more and more of us are taking delivery of our first electric car, pulling away from the lights much faster than the petrol heads while fuelling a significant increase in the national electricity demand.

Furthermore, with the advent of renewables, the problem of balancing supply and demand within the National Grid is become ever more challenging, leading to periods of excess demand and ‘negative electricity prices’. 

And with all this comes an increasing expectation of power cuts, grid constraints and increasing electricity costs.

Enter battery storage, and in particular, home battery storage. And smart meters, and smart electricity tariffs.

In January SunPower introduced the world’s first 400 Watt residential solar panels.

Utilising 104 Monocrystalline Maxeon Generation III solar cells, the panels have an efficiency of 22.6%. 

The panels have ‘standard’ panel dimensions of approximately 1.69m x 1.05m, giving an output of 226W per square metre.

As always with SunPower, the panels have a premium look…

When the government announced in 2018 that it would close the Feed-in Tariff scheme with effect from 31st March 2019, it failed to put in place any replacement for the Export Tariff. Small scale solar PV systems installed after 31st March were likely to end up exporting excess solar generation to the grid for free.

Not surprisingly there was uproar within the industry at this prospect.

In response, the government has this week launched a consultation on the Smart Export Guarantee (SEG).

Back in July, the government announced its intention to close the Feed-in Tariff Scheme to new entrants from 31^st March 2019.  The Export Tariff was scrapped at the same time, thus placing owners of small scale solar systems installed after 1^st April 2019 in a position whereby they could find themselves exporting excess solar electricity to the Grid for free.

Not surprisingly the idea of the homeowner installing solar only to find themselves subsidising the Big 6 with free exported solar electricity has caused something of an outcry in the solar industry…

"Can I go off-grid with solar?" is a question we are asked at least once a week. When the Big 6 hike electricity prices, make that once a day.

It's a particularly enticing proposition, especially if you are 'self-building' your dream home and aiming for PassivHaus standards and Grand Design prizes.

The short answer is "Yes you can go off-grid with solar."

A better answer is "Don't do it unless your grid connection is really expensive." Instead, make the grid work for you by taking full advantage of time-of-use tariffs (off-peak charging).

To illustrate our better answer, we've modelled an off-grid residential property with an annual electricity consumption of 5,000 kWh.

As you may know, the Feed-in Tariff solar subsidy scheme ends in March 2019.

After that, solar PV (solar electricity) has to stand on its own two feet.

The question is, can solar PV stand on its own two feet? 

And more to the point, if you can’t make the March 2019 installation deadline, should you still consider solar for your own property?

Equally if you want to extend your system (which wouldn’t qualify for subsidy even if you were to extend before March 2019), should you do so?

To help you work that out, we’ve launched a brand new Solar PV Calculator...