gangzoom Posted November 14, 2019 Share Posted November 14, 2019 (edited) What seems like a long long time ago 6 other people bought a Tesla using my referral code, Tesla than told me they were going to install a PowerWall home battery as a 'Thank You' gesture....... I think that was back in 2016, pretty much forgot about the whole thing, than a few months ago had a call from a local Solar panel install company. Tesla had sent them a PowerWall and they had been told to install it in my house and would be OK to come and do a site visit! The install took place a week a go, and PowerWall is now in and doing its thing. The hardware is a really nice bit of kit, almost silent and doesn't get warm. Apparently has a 10 year warranty and like all things Tesla do its the UI software that's a killer feature. Fully integrated into phone App, allows real time data feed on power distribution in the house, and controls such a off peak E7 charging. It can push/pull at 5KW which is alot of power. Looking at the data from last week it shows how little impact solar PV has in UK The main use at the moment though is the ability to charge the battery using cheap E7 electricity (like the car) and than avoid having to use any 'peak' rate electricity for the rest of the day. Since the install we've only used 3kWh of 'day' time electricity versus over 200kWh of E7 rates!! Our energy supplier is going to have a hissy fit! Overall its a very impressive bit of kit, though not worth the £10k all in costs if you had to pay for it with your own money. You can do something similar with off the shelf DIY kit for cheaper, but clearly getting the software/gateway to work properly isn't something more people can DIY! I can see how localised grid storage can really help deal with peaks in demand and stabilise grid demand overall, just load shifting a small number of houses away from evening peak in electricity demand will really take the strain off the system as a whole. Solar though in the UK is clearly not useful in winter months, even a massive 8KW array wouldn't get any where near covering electricity demands if your charging an EV. I wouldn't have paid for this my self, but when its 'free' whos going to say no? If you are a geek like me, the data it provides on household electricity use alone is really fascinating. But I am really interested how Bulb, our energy supplier is going to react to us now that we are effectively only using half price E7 electricity rate 100% of the time, something which I suspect they have never seen before! Edited November 14, 2019 by gangzoom Quote Link to comment Share on other sites More sharing options...
Ebized Posted November 14, 2019 Share Posted November 14, 2019 Does that allow you to sell excess energy back to the 'National Grid? Quote Link to comment Share on other sites More sharing options...
rabbitstew Posted November 14, 2019 Share Posted November 14, 2019 If Bulb are anything like British Gas they will not even notice. Last summer BG didn't notice that my daily gas usage went from something like 50p a day to £20 a day for 2 weeks, then went down to normal. Even in winter when my wife puts the heating on full blast all day we only used £5 of gas per day. When I raised it with them, they just said meters dont lie. The fact it was working correctly now clearly showed that it wasnt a fault with the meter as they dont just "fix themselves", I must have used the gas and they transferred me to a "how to use your energy more efficiently" team who told me useful stuff like turning the heating off when not at home etc.. When I asked what an earth would I have to be doing to use £20 of gas a day in the middle of summer when it was 36 degrees outside, they had no explanation at all and just repeated their "meters dont lie so you must have used it" line. Looking back through 3 years worth of usage, ive never used more than £6 a day. In fact, my entire street combined probably didnt use £20 of gas in a day in summer. But there you go. That's customer service for you! That Tesla power wall looks pretty awesome, but like you say £10k!!!! Quote Link to comment Share on other sites More sharing options...
gangzoom Posted November 14, 2019 Author Share Posted November 14, 2019 You can export, and some new tariffs let you, but am currently using all the power I can generate. Summer might be different. The tech is great, just a shame its so expensive - makes EVs look reasonably priced! Some energy supplier like Octopus are starting to offer interesting traiffs for people who can load shift Quote Link to comment Share on other sites More sharing options...
gangzoom Posted May 23, 2020 Author Share Posted May 23, 2020 Last couple of months with sun the PowerWall is starting to show it's real potential. Essentially since the mid April our house is almost using no grid electricity!! This is my electricity bill for last 30 days. Despite having less than ideal SE/SW solar PV, there are days when we are generating more electricity than we can use. Yesterday at 5pm the PowerWall was at 100%, the EV at 90%, eletric water heater was off because the water was hot and we still ended up exporting 4kWh to the grid!! I estimate half of our reduction in electricity usage is due to not doing so many miles in the car, currently 350 mile a month down from over 1000 miles a month. Some of that is because am doing more miles on the pedal bike, around 200 miles a month, but still it's pretty impressive performance by the PowerWall. If this level sun keeps up our electricity bill for 6 months+ of the year will be crazy low. Our standing charge for electricity is currently triple the cost of our actual electricity usage! Quote Link to comment Share on other sites More sharing options...
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