Why did we install Solar Panels and two Tesla Powerwalls?
This summer, we installed solar panels and two Tesla Powerwall batteries. This article accompanies my first solar/battery YouTube video.
So, was solar worth it?
Yes - but sort of.
In six months We saved over 1,172kg of CO from being released into the atmosphere as a result of generating our own power and not importing it from a natural gas power station and have generated 4.52MWh of energy. That's worth a little over £1,000 at the current energy prices.
Whilst we are currently operating our solar and powerwall system at a 'loss' as we are making capital plus interest repayments, should energy prices continue to increase as they have done in the UK for example (the Isle of Man has -temporarily- the cheapest energy in the British Isles), then the system will have broken even on an ongoing basis.
The target price for us is 81% or 30.58pence per kWh. We made this prediction back in early March 2022 and although we are not in the UK - the UK's price cap (Energy Price Guarantee) has capped energy prices at 34p/kWh. If our prices reached these dizzying levels our investment will have been a good one in the short term.
34 pence per kWh from October'22-March'23. Craziness:
Department for Business, Energy & Industrial Strategy
The spreadsheet download link for members is at the top of this post and in your most recent email from us. If you aren't a member yet - you can join our mailing list for free below and return to this page for your download link.
Just a note about the spreadsheet: it wasn't originally designed for the public - it's just something that I wrote while figuring out whether and what type of system would be best fit for us. As many people have asked me for a copy, here it is but it definitely could be better and improved on. If you have any ideas or spot anything that needs amending or improving or making easier to understand, email me and I'll update the sheet for everybody to benefit!
I hope the use is straightforward, and these are our figures. You can see we need '2.69' powerwalls and the current break even point should energy prices remain as they are is nearly 18 years. But as I say in the video - I don't believe our current energy prices are sustainable in the long term.
The above chart is based upon a simulated 3D model of the panels, taking panel location and positioning, attitude/angle and climate into account. Produced from the SolarEdge software which we have found to be a little conservative in its estimates (although climate prediction has a wide error margin!).
This project is ongoing, and I promise to update you on how it goes over the winter and the spring of 2023.
Thank you
I appreciate you taking your time to watch my video(s) and read the article. If you need any assistance with making that spreadsheet clearer to understand or use please email me.
Have a fabulous festive December!
- Mike
