Adrian Walker Posted July 31, 2019 Share Posted July 31, 2019 "Right now, when the electricity grid runs short of capacity during peak periods, extra power can be generated but usually not in the cleanest or greenest way. Conversely, when there’s excess renewable generation, demand cannot be increased which leads to wasted energy. That’s why EDF Energy is building a network of small-scale batteries to help balance this mismatch. In return for helping balance the grid for 10 years, we’re offering a substantial upfront discount off the retail price of the battery." www.edfenergy.com/for-home/battery-storage Full spec of battery here Link to comment Share on other sites More sharing options...
Jeremy Harris Posted July 31, 2019 Share Posted July 31, 2019 2 minutes ago, Adrian Walker said: "Right now, when the electricity grid runs short of capacity during peak periods, extra power can be generated but usually not in the cleanest or greenest way. Conversely, when there’s excess renewable generation, demand cannot be increased which leads to wasted energy. That’s why EDF Energy is building a network of small-scale batteries to help balance this mismatch. In return for helping balance the grid for 10 years, we’re offering a substantial upfront discount off the retail price of the battery." www.edfenergy.com/for-home/battery-storage Full spec of battery here Interesting offer. EDF are claiming that the price includes a discount, but over £7k for 8.2 kWh is nearly £3k more than I've been quoted for a 9.6 kWh system, so it's not fantastic value. The 9.6 kWh system I've been quoted has a 10 year warranty, the same as the Powervault. 1 Link to comment Share on other sites More sharing options...
K78 Posted July 31, 2019 Share Posted July 31, 2019 Will be interesting to see where we are with home battery technology in 5 years or so. Entry point is still way to high for me. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted July 31, 2019 Share Posted July 31, 2019 5 minutes ago, K78 said: Will be interesting to see where we are with home battery technology in 5 years or so. Entry point is still way to high for me. I've been watching prices for a year or two now and they are steadily reducing, but not by enough to make them viable, in terms of paying back the investment through lifetime cost savings. Not far off, though, the 9.6 kWh system I recently had a quote for is within about 10% of break-even, and with the added benefit of providing a backup power supply (for us, we get lots of power cuts) it seems worth investing in. I've no doubt that prices will continue to fall, though, as most of the price is in the battery packs, and the prices of those seems to be falling as a consequence of the increased popularity of electric vehicles. I'm not yet convinced that electric vehicle cells are best suited to home storage, though, because of potential cycle life issues. Redox flow batteries seem to be a promising home storage technology, as they potentially have a long life, if the capacity loss issues that have been seen with electrode degradation can be resolved . The snag is that they aren't suitable for electric vehicles, which seems to be the mass market driver for battery development, and so not a lot of development cash is being spent on them. Redox flow batteries are about at the same stage of development as lithium ion chemistry was around 15 years ago, when they were also suffering from problems related to electrode composition. 3 Link to comment Share on other sites More sharing options...
dnb Posted July 31, 2019 Share Posted July 31, 2019 It is an interesting offer, especially for me at my current state of build. But they aren't giving much away are they? I suppose the argument is that they are servicing it for 10 years. 3 hours ago, JSHarris said: I'm not yet convinced that electric vehicle cells are best suited to home storage, though, because of potential cycle life issues. And they are designed for a different usage profile. Peak currents are very different between battery based energy storage for houses and the use (or abuse in my case) batteries in an electric car see. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted August 1, 2019 Share Posted August 1, 2019 8 hours ago, dnb said: It is an interesting offer, especially for me at my current state of build. But they aren't giving much away are they? I suppose the argument is that they are servicing it for 10 years. And they are designed for a different usage profile. Peak currents are very different between battery based energy storage for houses and the use (or abuse in my case) batteries in an electric car see. Not sure there is any servicing to do, though. The battery pack in my car doesn't get serviced, neither does the inverter on the PV system, so really all servicing can ever be is a check that the system is still working. As for peak current, certainly a house system places a much lower demand on the battery than a car, but cars don't really place a high peak current demand on their battery packs either. My car draws a maximum of under 5C from the pack under hard acceleration, which is about the rating that cheap lithium cells from 20 years ago could tolerate. Getting cells to deliver 20C to 25C is now commonplace, with some cells being well able to deliver around 40C, so even a Tesla isn't really placing much of a demand on its battery pack (a dual motor Model S Performance with its 100 kWh pack, in Ludicrous mode, only draws about 6C from its pack at maximum acceleration). Link to comment Share on other sites More sharing options...
dpmiller Posted August 1, 2019 Share Posted August 1, 2019 What size of inverter is associated with these battery packs tho? Link to comment Share on other sites More sharing options...
SteamyTea Posted August 1, 2019 Share Posted August 1, 2019 (edited) 48 minutes ago, JSHarris said: in Ludicrous mode, only draws about 6C from its pack at maximum acceleration That's interesting, never thought about it. 8 minutes ago, dpmiller said: What size of inverter is associated with these battery packs tho? Probably no more than 3.68 kW or 16A. But I suspect smaller. But they are not off-grid or islanding systems. Edited August 1, 2019 by SteamyTea Link to comment Share on other sites More sharing options...
Jeremy Harris Posted August 1, 2019 Share Posted August 1, 2019 Just now, dpmiller said: What size of inverter is associated with these battery packs tho? It varies. The system I've been looking at can deliver 3.6 kW, but that can be increased by adding additional inverters (they can be paralleled up). For us, 3.6 kW is more than enough, as we want to use the battery pack to offset peak rate electricity use in winter (so charging the pack overnight from E7, when there's little PV generation) and offset the import of electricity around the clock in the months when we generate a fair bit from PV. The peak loads are a very small part of the energy usage, and not really worth sizing the inverter for. The heating runs from E7, so would be on in parallel with battery charging in winter and the cooling runs from excess PV generation, so would just slightly reduce the amount by which the battery could be charged in summer. In summer, we need a steady 200 to 300 W overnight to offset grid import, which should be no more than about half the battery pack capacity of 9.6 kW at most. In winter we need roughly the same to offset peak rate import during the day, perhaps a little more. Link to comment Share on other sites More sharing options...
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