adam2 wrote:There is nothing wrong in adding to long dormant threads, indeed this can be preferable to starting a new discussion on the same subject.
Totally agree. Indeed, some of those old threads are fascinating. Such as this one from just about 11 years ago.
Pauls Mobbs wrote:Your central heating pump is rated at around 500 to 1000 watts (in practice it might draw only 200W to 600W of continuous power, depending on the size of the system). A square metre of PV might, and an average bright day, produce 40 to 80 watts per square meter (amorphous cells produce about half the power of monocrystalline/polycrystalline silicon, but for the sake of the maths let's call it 50). In terms of instantaneous power you're going to need 10 to 20 square metres, plus about 20% for the inverter efficiency losses = 12 to 24 sq.m of PV to run the central heating pump directly!
The alternative is to charge a large battery bank for a long period of time and then use the power directly for the short periods it's needed. Let's aim at 480 watts of continuous power as our target figure. Producing 240W from 12 volts will require (240/12) 20 amps. Add the inverter losses on top (say 20%) we multiply by 1.2 = 29 Amps. Running your pump for 1 hour (which more than is enough to defrost the house to stop the pipes freezing -- which is my major concern) will therefore take 29Amp-hours. However, the charge/discharge cycled on the batteries will be between 20% and 40% efficient (depending on their age) and so you'd actually have to scale the PV array by this factor to get that amount of power outr of the storage again.
These are still relevant, useful data and will continue to be.
I experience pleasure and pains, and pursue goals in service of them, so I cannot reasonably deny the right of other sentient agents to do the same - Steven Pinker
So it appears as though if you want your electricity to be generated from renewables sources, independent suppliers should be your port of call, but if that won't do, e.on or British Gas are the next best thing .
It's all very well if people demand their power is supplied only from renewables, but there are sources which make up the total supply. If you look at www.gridwatch.templar.co.uk it shows the available sources. It also shows how the amount from each of the sources vary, if you look often enough.
Picking one supplier that claims 100% renewables, if the wind doesn't blow and it is a cloudy day can they supply all their customers from only renewables? I think this is fanciful. There are times when little wind blows in the evenings at peak times, and from gridwatch you can see that coal and gas output goes up to fill the gap.
The best way to to be eco-friendly is turn of electrical appliances and encourage local authorities to turn out street lights. (Oh and get rid of your dog). Then you will suffer the wrath of the sheeple who don't give a stuff and think it can be BAU.
To become an extremist, hang around with people you agree with. Cass Sunstein
I get what you are saying. And I agree, 100 per cent renewables isn't sustainable. But, people do at least have a choice of having some of their electricity being generated through renewable sources.
Personally, I am a customer of an energy supplier with little electricity generated from renewable sources but I will be switching soon.
Switch as much as you like, the proportion of the electricity delivered from renewables will be the same as for every other user. The "suppliers", i.e. companies you might pay, buy electricity from the producers. They may choose to pay only producers who use renewable sources, but the electricity that comes down your wires, and everyone elses wires, is very nearly the same, and for adjacent properties is identical, even if they use a supplier that buys from say, EDF.
When strong winds blow and you buy from Ecotricity, and there is a power cut in your area, you will be cut off the same as surrounding properties, renewables or not. You don't have a choice of where your electricity comes from, you only choose which firm gets the chance to make a profit.
To become an extremist, hang around with people you agree with. Cass Sunstein
Pretty much the only influence switching suppliers does is switch what the supplier spends your money (its profits) on. Some suppliers give most/all of the profits back to shareholders whereas some suppliers spend most/all of the profits on building renewable energy generation infrastructure.
If you want to make a difference with your energy bill its only worth buying from a supplier who is spending their profits on building infrastructure - even if what they are currently supplying isn't 100% renewable! Using a 100% renewable supplier, who isn't building is pointless.
woodburner wrote:Switch as much as you like, the proportion of the electricity delivered from renewables will be the same as for every other user. The "suppliers", i.e. companies you might pay, buy electricity from the producers. They may choose to pay only producers who use renewable sources, but the electricity that comes down your wires, and everyone elses wires, is very nearly the same, and for adjacent properties is identical, even if they use a supplier that buys from say, EDF.
When strong winds blow and you buy from Ecotricity, and there is a power cut in your area, you will be cut off the same as surrounding properties, renewables or not. You don't have a choice of where your electricity comes from, you only choose which firm gets the chance to make a profit.
I'm not going to "switch as much as I like". My tariff is coming to end soon, so I will switch the once. I will choose an energy supplier that is at least committed to bettering its fuel mix. I understand your point regarding having no choice where my electricity is generated, but I do have a choice of who supplies my electricity don't I?
ericgarmin wrote:I get what you are saying. And I agree, 100 per cent renewables isn't sustainable. But, people do at least have a choice of having some of their electricity being generated through renewable sources.
Personally, I am a customer of an energy supplier with little electricity generated from renewable sources but I will be switching soon.
100% renewable is sustainable but it isn't practicable at the moment. When we have more than enough renewables to supply instantaneous demand and a method of storage of surplus electricity to cover times of deficient generation, 100% renewables will be sustainable.
I agree that switching to a renewable supplier is a good thing because they are investing 100% in more renewables whereas conventional suppliers aren't to the same degree.
It was once, then the human population increased dramatically, that put an end to it, and there's only one way to get back there. We know the way will not be a comfortable one.
To become an extremist, hang around with people you agree with. Cass Sunstein
woodburner wrote:Switch as much as you like, the proportion of the electricity delivered from renewables will be the same as for every other user. The "suppliers", i.e. companies you might pay, buy electricity from the producers. They may choose to pay only producers who use renewable sources, but the electricity that comes down your wires, and everyone elses wires, is very nearly the same, and for adjacent properties is identical, even if they use a supplier that buys from say, EDF.
When strong winds blow and you buy from Ecotricity, and there is a power cut in your area, you will be cut off the same as surrounding properties, renewables or not. You don't have a choice of where your electricity comes from, you only choose which firm gets the chance to make a profit.
I'm not going to "switch as much as I like". My tariff is coming to end soon, so I will switch the once. I will choose an energy supplier that is at least committed to bettering its fuel mix. I understand your point regarding having no choice where my electricity is generated, but I do have a choice of who supplies my electricity don't I?
I would say you don't have a choice of who supplies your electricity, you just have a choice of who you pay for it.
To become an extremist, hang around with people you agree with. Cass Sunstein
woodburner wrote:
I would say you don't have a choice of who supplies your electricity, you just have a choice of who you pay for it.
Yes there is only one set of lines in an area owned by one company or co-op. Some governments have allowed people to buy from a number of suppliers but you still have to pay your local supplier for maintaining the lines.
My own REA Co-op is one of the oldest in the USA if not the oldest. They are small enough to have gone one hundred percent renewable by combining hydro power from Quebec and local dams with power they generate from methane coming out of the states largest landfill. As long as there is garbage We will have lights.
They sent me a capital credits check with my December bill making my months electricity cost just US $24.75.
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