Homeowner Blog

Today is a big day at Spirit Energy.

It’s our 10th anniversary.

Most importantly we are celebrating with a big cake, but we have also taken time to review some of the milestones reached within the last 10 years, both at Spirit and within the wider community, focusing on cleaner air, climate change mitigation and sustainable fuel supply.

Another year has gone by with Tesla roof tiles as popular as ever in the public imagination, yet still mostly intangible. But that could all be about to change. Elon Musk has announced Solarglass, the latest iteration of his solar tiles with promises of improved technology and scalability. The company is aiming to ramp up to 1000 installations a week in America, so what can we expect?

In the wake of the largest climate protests the world has ever seen, we have dug a little deeper in our own back yard to assess the ‘life time’ carbon footprint of a solar system...

This year saw the Feed-in Tariff closed to new applicants, leaving a very different landscape to the heady days of 2010, when the feed-in tariff scheme was first launched and the subsidy was around 43p per kWh. So, are solar panels worth it today?

Speaking purely from a financial point of view, the answer is a resounding yes. Of course beyond the financial, there are many other environmental benefits to be gained from installing solar, installing residential battery storage, driving an electric vehicle etc. Not least because they all contribute directly or indirectly to tackling air pollution, which, we are told, is gradually destroying the nation's health.

Back to the financials. The solar subsidy may have fallen, but so has the cost of the technology. Overall the cost of domestic solar electricity is now around 9p per kWh. This is well below the p average domestic import cost from the grid (which, by the way, increased by 7% in the last 12 months...).

Yesterday I had my own modest version of a Victor Kiam moment.

If you are too young to remember Mr Kiam, spend 30 seconds watching this…. Mr Kiam's famous line ‘I loved the shaver so much I bought the company’ was the cornerstone of a hugely successful 1979 advertising campaign.

Mr Kiam was swept away by the joy of a sharp shave. For me it was Tesla and the sheer passion with which they are pursuing their mission ‘to accelerate the world’s transition to sustainable energy’.

Around 30 GigaWatts of the UK’s older fossil fuel and nuclear capacity is due to be de-commissioned 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 whilst 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.

Is electricity cheaper at night?

If like me, your gut answer is ‘of course electricity is cheaper at night’, read on …

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….

The long-awaited Powerwall 2 backup capability is ‘on the water’, with the first wave of deliveries expected in April.  There’s a two stage roll-out, based on the type of earthing system required. Stage 2 will be in August.

If you are familiar with the Powerwall system, you will know that the system consists of the Powerwall unit itself, which houses the battery and the inverter, along with a ‘gateway’ which provides remote connectivity.

The original gateway, ‘GW 1’, was a plastic fronted box providing remote connectivity to the system.

From April this will be upgraded to a new gateway, GW 2, a stylish frosted glass-fronted ‘mini’ version of Powerwall 2, measuring 380mm wide x 580mm tall x 127mm deep, and weighing 9.8kg.  It is IP55 rated, so suitable for outdoors, and can be padlocked to stop any unwanted access.

The main purpose of the gateway upgrade is to enable ‘backup’ capability so that the homeowner can still power their home in a power cut.

So confident is Tesla that all customers will want the new backup enabled system, that they are actually expecting to discontinue GW 1 altogether, even though GW 1 offers a lower cost entry point into the Powerwall 2 system.

Tesla has certainly done its research. According to the company, in the nine month period 18/6/18 – 18/2/19 there were 93,965 unique power cut incidents in the UK, typically lasting between 15 mins and 4 hours and impacting 2 million customers. Anyone with a solar panel backup system in place would be smiling now....

[Apparently there are 22,200  online searches for "Schadenfreude" every month in the UK.  I wonder if Mr Musk has checked that stat out ....]

A few weeks ago we launched a Solar PV Calculator and wrote a blog about solar in a post subsidy world.

However, for many people looking at renewables, solar is only one part of the story. Increasingly, solar goes hand-in-hand with battery storage. And many of us are at least wondering whether we should switch to an electric car.

Finally, in 2019 we expect to see a proliferation of ‘time-of-use’ electricity tariffs from the utility companies, all aimed at transforming electricity demand and supply.

To handle all of this, we’ve been busy developing the all-singing-and-dancing calculator which looks at the package of solar, battery storage, electric car usage and choice of tariff. And of course if you are building your dream home, you'll probably be wanting a heat pump...

Soft Launch of Version 1 Today

Call me a nerd but I love a mathematical model…