pulhamdown Posted October 23, 2019 Share Posted October 23, 2019 Apologies if this is in the wrong section. I couldn't access the one I wanted. Anyway, I see SSE has introduced a "1 year fix and drive tariff", allowing up to 2000 kW hours of free charging between 12.00 midnight, and 7.00am. A "smart meter" is compulsory. This looks like a no brainer when we get an EV, as we already have a fully paid off solar PV system. It looks like an off peak set up, but without a separate meter. Has their "smart meter" actually become smart? What's the catch? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted October 23, 2019 Share Posted October 23, 2019 It's an incentive scheme to get people to have a "smart" meter fitted. Once you have a "smart" meter you cannot get it switched back to a standard one, and so can be subject to any variable tariff scheme that the suppliers come up with. The suppliers are desperate for more people to have "smart" meters, as it enables then to reduce their risk in buying wholesale electricity on the 30 minute slot, buy-ahead, spot market. They can vary tariffs every 30 minutes to consumers if they wish, so once people have "smart" meters it's going to be pretty hard to compare one supplier with another as far as price goes. I've been trying to track the Octopus Agile tariff (which is a variable rate one) with our standard E7 tariff, and it's incredibly difficult to do. Right now, many of the "smart" meter incentive tariffs look quite attractive, but I can't see this lasting, TBH. 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted October 23, 2019 Share Posted October 23, 2019 Sounds like Economy 7. What are the unit prices and the meter rental charges. 2000 kWh would cost me about 180 quid. Link to comment Share on other sites More sharing options...
scottishjohn Posted October 23, 2019 Share Posted October 23, 2019 (edited) that would be fine if you could use it for other things as well. if you had 2 ponds you could use that free stuff to do your own pumped storage generation with a small micro hydro unit.LOL HMMMMM thinks +plots just looked at it its 2000kw ayear --so 5.5 kw per day unless other unti prices go crackers on this system --its a no brainer -as no exit cost from scheme Edited October 23, 2019 by scottishjohn Link to comment Share on other sites More sharing options...
pulhamdown Posted October 23, 2019 Author Share Posted October 23, 2019 9 minutes ago, scottishjohn said: That would be fine if you could use it for other things as well. Surely there's no "smart meter" bright enough to detect the difference between a car charging, and a dishwasher on a midnight mission.? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted October 23, 2019 Share Posted October 23, 2019 (edited) 14 minutes ago, scottishjohn said: that would be fine if you could use it for other things as well. if you had 2 ponds you could use that free stuff to do your own pumped storage generation with a small micro hydro unit.LOL HMMMMM thinks +plots just looked at it its 2000kw ayear --so 5.5 kw per day unless other unti prices go crackers on this system --its a no brainer -as no exit cost from scheme Most domestic supplies are rated at well over 5.5 kW, in theory ours is rated at 23 kW. Car charging normally runs at around 6.5 to 7 kW, so if there's a 5.5 kW maximum power limit then that means turning the car charge rate down. Added: Is there a mix up between power and energy here? 2,000 kWh is about 5.5 kWh per day. That then makes more sense. 2,000 kWh would be around 8,000 miles in most EVs. Edited October 23, 2019 by JSHarris Added afterthought 1 Link to comment Share on other sites More sharing options...
scottishjohn Posted October 23, 2019 Share Posted October 23, 2019 1 minute ago, pulhamdown said: Surely there's no "smart meter" bright enough to detect the difference between a car charging, and a dishwasher on a midnight mission.? my guess its a separate line which goes to a car charging socket . a lloose lead that connects from that to your ASHP? free heating for all!! Link to comment Share on other sites More sharing options...
scottishjohn Posted October 23, 2019 Share Posted October 23, 2019 Just now, JSHarris said: Most domestic supplies are rated at well over 5.5 kW, in theory ours is rated at 23 kW. Car charging normally runs at around 6.5 to 7 kW, so if there's a 5.5 kW maximum power limit then that means turning the car charge rate down. more like after you reach 2000kw --you then pay for it Link to comment Share on other sites More sharing options...
scottishjohn Posted October 23, 2019 Share Posted October 23, 2019 He,HE if you ran a micro hydro on the free powerand then sold it back them .LOL Link to comment Share on other sites More sharing options...
Jeremy Harris Posted October 23, 2019 Share Posted October 23, 2019 1 minute ago, scottishjohn said: more like after you reach 2000kw --you then pay for it But you can never, ever draw anything close to 2,000 kW from any domestic supply. Most are limited to an absolute maximum of 100 A, which is about 23 kW. Link to comment Share on other sites More sharing options...
scottishjohn Posted October 23, 2019 Share Posted October 23, 2019 come on --I know that but you could use it up alot quicker than 5.5kw perday --then you pay for anything over your yearly free allowance Link to comment Share on other sites More sharing options...
Jeremy Harris Posted October 23, 2019 Share Posted October 23, 2019 6 minutes ago, pulhamdown said: Surely there's no "smart meter" bright enough to detect the difference between a car charging, and a dishwasher on a midnight mission.? Yes, not at all hard to do. "smart" meters log and report usage to a reasonably fine level over the network, and the data can be analysed and an approximation as to what type of device is being used can easily be determined. For example, a load increase (or decrease) of about 3 kW, for a period of an hour or two, would almost certainly be an immersion heater. A similar load switching on and off several times for a period of an hour or so would probably be an oven. A load of around 7 kW on for several hours pretty much has to be a car charge point. A load that comes on at a modest level, then reduces over time, is probably an ASHP. Tracking energy usage, and correlating it with the time of day, day of week, outside temperature, etc, could allow a pretty accurate pattern of use for all fairly large appliances in the house to be built up by your energy supplier. By doing this, they get a better profile of you as a customer, so can then target you for a range of purposes, which may include selling the data they collect to third parties (for example, knowing your pattern of use of an electric car would be of interest to insurers, car suppliers, etc). 1 Link to comment Share on other sites More sharing options...
scottishjohn Posted October 23, 2019 Share Posted October 23, 2019 wee change of subject and i know you will have answer at hand 12dc --40max load --30m long cable --what size needed its for local clayshooting club Link to comment Share on other sites More sharing options...
scottishjohn Posted October 23, 2019 Share Posted October 23, 2019 2 minutes ago, JSHarris said: Yes, not at all hard to do. "smart" meters log and report usage to a reasonably fine level over the network, and the data can be analysed and an approximation as to what type of device is being used can easily be determined. For example, a load increase (or decrease) of about 3 kW, for a period of an hour or two, would almost certainly be an immersion heater. A similar load switching on and off several times for a period of an hour or so would probably be an oven. A load of around 7 kW on for several hours pretty much has to be a car charge point. A load that comes on at a modest level, then reduces over time, is probably an ASHP. Tracking energy usage, and correlating it with the time of day, day of week, outside temperature, etc, could allow a pretty accurate pattern of use for all fairly large appliances in the house to be built up by your energy supplier. By doing this, they get a better profile of you as a customer, so can then target you for a range of purposes, which may include selling the data they collect to third parties (for example, knowing your pattern of use of an electric car would be of interest to insurers, car suppliers, etc). big broither is watching as usual Link to comment Share on other sites More sharing options...
Jeremy Harris Posted October 23, 2019 Share Posted October 23, 2019 1 minute ago, scottishjohn said: come on --I know that but you could use it up alot quicker than 5.5kw perday --then you pay for anything over your yearly free allowance OK, so if this just a mix up over units then? Do you mean "5.5kw per day", as that is only about 0.229 kWh Just to be clear, 5.5 kW is a measure of power, a bit less than the power drawn by most EV charge points. 5.5 kWh is a measure of energy, enough electricity to allow many EVs to drive for around 22 miles. Link to comment Share on other sites More sharing options...
scottishjohn Posted October 23, 2019 Share Posted October 23, 2019 (edited) 2 minutes ago, JSHarris said: OK, so if this just a mix up over units then? Do you mean "5.5kw per day", as that is only about 0.229 kWh Just to be clear, 5.5 kW is a measure of power, a bit less than the power drawn by most EV charge points. 5.5 kWh is a measure of energy, enough electricity to allow many EVs to drive for around 22 miles. yep they are giving you 2000kwh - if not then they are giving you sod all just checked it is 2000kwh--8000miles they Edited October 23, 2019 by scottishjohn Link to comment Share on other sites More sharing options...
Jeremy Harris Posted October 23, 2019 Share Posted October 23, 2019 2 minutes ago, scottishjohn said: wee change of subject and i know you will have answer at hand 12dc --40max load --30m long cable --what size needed its for local clayshooting club Depends very much on the maximum allowable voltage drop. If it was acceptable to only deliver 11.5 VDC at the remote end (so a voltage drop of 0.5 V) then ~85mm² cable would be needed. Link to comment Share on other sites More sharing options...
scottishjohn Posted October 23, 2019 Share Posted October 23, 2019 1 minute ago, JSHarris said: Depends very much on the maximum allowable voltage drop. If it was acceptable to only deliver 11.5 VDC at the remote end (so a voltage drop of 0.5 V) then ~85mm² cable would be needed. i came up with a silly size like that ,but another on line calculator said 16mm2 Link to comment Share on other sites More sharing options...
scottishjohn Posted October 23, 2019 Share Posted October 23, 2019 10.5 is normal acceptable on car systems -ecu,s will work fine to 10v Link to comment Share on other sites More sharing options...
Jeremy Harris Posted October 23, 2019 Share Posted October 23, 2019 23 minutes ago, scottishjohn said: 10.5 is normal acceptable on car systems -ecu,s will work fine to 10v 1.5 V drop over 30m (so 10.5 VDC at the end), at 40 A, will give a cable size of ~27mm², so the nearest size would be 25mm², accepting a slightly higher voltage drop. Link to comment Share on other sites More sharing options...
PeterW Posted October 23, 2019 Share Posted October 23, 2019 41 minutes ago, scottishjohn said: wee change of subject and i know you will have answer at hand 12dc --40max load --30m long cable --what size needed its for local clayshooting club That is ~500w so a cheap £30 inverter at the 12v end, 1.5mm2 230v extension lead and then 500w transformer at the load end. Change from £100 tops, far cheaper than a big fat cable. Link to comment Share on other sites More sharing options...
SteamyTea Posted October 23, 2019 Share Posted October 23, 2019 1 hour ago, JSHarris said: A load of around 7 kW on for several hours pretty much has to be a car charge point Or my water heating and two storage heaters. Link to comment Share on other sites More sharing options...
scottishjohn Posted October 23, 2019 Share Posted October 23, 2019 1 hour ago, PeterW said: That is ~500w so a cheap £30 inverter at the 12v end, 1.5mm2 230v extension lead and then 500w transformer at the load end. Change from £100 tops, far cheaper than a big fat cable. that would be fine --but no mains supply to site --its all batteries Link to comment Share on other sites More sharing options...
Jeremy Harris Posted October 23, 2019 Share Posted October 23, 2019 38 minutes ago, SteamyTea said: Or my water heating and two storage heaters. But it's unlikely that they would have the same combined power signature as an EV charge point. A charge point tends to run for around 90% of the on time at maximum power, then it gradually reduces power during the balancing phase of the charge at the end. A couple of storage heaters and an immersion are likely to each switch off asynchronously, with a pattern that could be correlated with the weather, so I'd guess that it would be reasonably easy to determine the most likely cause of the load pattern. The hot water usage is probably fairly consistent, whereas the storage heaters will probably vary their charge roughly in proportion to the weather, I'd guess. Link to comment Share on other sites More sharing options...
Ed Davies Posted October 23, 2019 Share Posted October 23, 2019 1 hour ago, scottishjohn said: that would be fine --but no mains supply to site --its all batteries @PeterW is suggesting making your own “mains”. That's what the inverter is for. (But I'm a bit doubtful about a cheap modified-square-wave inverter feeding a reactive load like a transformer.) Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now