As everyone knows, we are facing a future climate of massive energy price increases and we are particularly at a disadvantage with our current setup, with the way our Temporary Living Quarters are constructed. Since they were only temporary, we had originally put in minimal insulation into the walls and ceiling, but the Sun Corridor is the main culprit in terms of energy losses, especially during the Winter and Spring months.

We have plans to reduce this loss for the next Winter / Spring periods, by shutting off half the Sun Corridor and also insert additional insulation into our bedrooms and living room too. This will hopefully reduce our running costs.

But, this really made us think about the whole world of renewable energy, capturing the solar energy in both electricity and thermal forms. Plus, also, what to do with this energy once we have caught it. This means some form of a storage system like batteries or underground water tanks. We have already explored the Thermal capturing and storage side of things, after all, we have five very large water tanks buried underground and they are ready to store the Sun’s energy once we have assembled the thermal solar panels on top of our Garage roof.

So, Stephen has been analysing and running simulations of what our house needs to keep it warm, what sort of electricity we might need to keep the “lights” on and what values of sunshine and temperature we get here. He found both NASA and ESA datasets describing the last ten years of recorded temperatures and sunshine falling on our corner of the world. He calculated the building’s energy losses, the solar gains via the windows and Skylight (as the Sun moves around the sky in the different times of the year etc.) and looked at our historical electricity usage. He then calculated the energy usage (heat & electricity) and generation for each hour of the day and night for a least a year.

Then, we started adding various combinations of Green solutions to the simulation runs. Like for example, our built-in solar electric panels in the Skylight (2200Watts over 11 panels), then extra panels on our P roof (faces slightly East of South) with various sizes, then did the same on the M roof (faces slightly West of South) with various number of panels as well.

All part of the simulation runs, are the calculations of how much money we would save on our electricity bills, and changing to combinations of different Green Solutions.

This includes our buried Energy Modules and also the Thermal Solar that we will have on the Garage roof too, all this got into the mix too.

So far, we have not looked at batteries yet, but we are getting a turnaround time of about 3 to 5 years to pay for the cost of the solar panels and the associated electronic control gear to handle it and that is assuming today’s prices of 20p per kiloWatt Hour. Just imagine how quickly we could pay off the investment if the price of electricity goes up even more, like 30p or 40p per kiloWatt Hour!!

But, this setup is purely a daytime only solution, and only when the Sun is shining too. We recognise that there will be times, perhaps quite a lot, where we don’t get enough sunshine to cover the basic energy requirement of our household. So, Stephen started investigating batteries, in particular, lithium-iron-phosphate (LiFePo) batteries that are designed for more robust applications and there is a growing market for these types. We can get hold of large batteries that has very good long life cycle times, in the order of six thousands (6,000) deep discharge and charge cycles. And, if the size of the battery is such that we only need one cycle for each day, then we would get about 18 years of life out of them. That is plenty of time to pay back the cost of buying all the batteries, with the money we would also save.

So, Stephen did many more simulation runs with different battery capacity, taking the solar electric to charge them up, but, also using national grid electricity during the off-peak night-time to tap into cheap nighttime rates and concluded that we could also pay back the cost of the batteries in the same 3 to 5 years.

Remember after the payback period all further savings are pure profit meaning the house will need very little money for heat and light.

This is very interesting and there was a great deal of discussions between us all, weighing up the pros and cons, what can we afford upfront and what we needed to do right now, to fend off the future price rises. We will decide soon, very soon.

By Shaun

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