Ask them how they prevent pigeons nesting under them. My neighbours were not popular when the flying rats decided that solar panels made great shelters for the nests.
Ours only have a 1 inch gap underneath, not enough for birds to nest in (plus it's too exposed/breezy for tiny birds). Not sure which fitters choose to install them with a big gap - bear in mind there are a range of fitters, some better than others.
If anything, the only potential issue (round here) is seagulls using the v-shape crevice at the very top to possibly build a nest in. But it hasn't happened yet, perhaps they find the panels too shiny/hot, although they do perch on the top edge occasionally.
Problem is that you are now starting to talk serious money and added complexity.
It need not get that complex, but problem is current systems are designed around generating subsidies, not electricity. A generator that you can't use in a power cut is dumb in only the way 'Green' power systems can manage..
With off line system where you manually isolate (you don't want to see the cost of online UPS), you have to think about how reliable the power is and what you are using it for.
Well.. I have UPS, as in large rack previously intended for a datacentre. And am in the process of converting stuff to run off DC.. which is something of a larger project. But if we were really serious about energy efficiency would be built into new builds.
(One challenge for new homes is having any space for a decent sized hot water tank. Perception is this is 'energy inefficient'. Go figure.)
Even in the middle of summer its 4kw maximum. Appliances like fridge and freezer will automatically start using it. If you have other devices on they will start using it but what happens if generation fluctuates, how will your appliances handle brown out ? Worse then total power failure almost certainly. And that is assume the power doesn't die when your panels are not generating, which is 3/4 of the time.
This is where a nice load of water helps. It's the cheapest form of 'renewable' energy store given the cost of storage tanks, and heating elements also being dirt cheap, low maintenance and not very fussy about power quality.. Rather than 'modern' homes with solar power, condensing boilers and no heat, hot water or power in a power cut. How does that make any sense?
Another issue is appliances. So you're potentially getting 'free' hot water. What do you then use it for if you've got an electric shower, and washing machine/dishwasher that only has a cold water inlet? But that again is a lack of joined-up thinking from industry.
All I am saying is yes its feasible but all the research I have done for domestic systems, unless you have a pressing need for UPS then I wouldn't bother adding the complexity and cost.
I think it's very feasible with hot water acting as your 'UPS'. It's just a heat store instead of an electricity store. Otherwise you're right and we really need to do more work on better/cheaper ways to utilise 'dirty' power.. Otherwise many of these 'Green' initiatives are really a waste of time, money and of course energy.
It need not get that complex, but problem is current systems are designed around generating subsidies, not electricity. A generator that you can't use in a power cut is dumb in only the way 'Green' power systems can manage..
Well.. I have UPS, as in large rack previously intended for a datacentre. And am in the process of converting stuff to run off DC.. which is something of a larger project. But if we were really serious about energy efficiency would be built into new builds.
datacentre racks don't have individual UPS, we have a UPS for the datacentre at my work but I'm guessing most people don't want a football field sized UPS install, even its its underground.
It you are talking rack mounted UPS designed to allow servers to do a graceful shutdown, you are talking 15 to 20 minutes of run time for a couple of servers. They would have a fit trying to power a house.
This is where a nice load of water helps. It's the cheapest form of 'renewable' energy store given the cost of storage tanks, and heating elements also being dirt cheap, low maintenance and not very fussy about power quality.. Rather than 'modern' homes with solar power, condensing boilers and no heat, hot water or power in a power cut. How does that make any sense?
Strange thinking, I am pretty certain that people don't want hot water in the event of a power outage, they want electricity.
Another issue is appliances. So you're potentially getting 'free' hot water. What do you then use it for if you've got an electric shower, and washing machine/dishwasher that only has a cold water inlet? But that again is a lack of joined-up thinking from industry.
Again, what use is hot water in the event of power failure ? Or even for storing 'excess' power. Why do thing people use combi-boilers ? All studies show that for most domestic systems, heating up water as and when needed it much more useful then heating up loads and storing it. That is why you get cold feed only appliances these days, its more efficient.
I think it's very feasible with hot water acting as your 'UPS'. It's just a heat store instead of an electricity store. Otherwise you're right and we really need to do more work on better/cheaper ways to utilise 'dirty' power.. Otherwise many of these 'Green' initiatives are really a waste of time, money and of course energy.
I think you SEVERELY overestimate how much excess power a domestic PV system is generating. A 180 litre hot water tank (a small one) would take around 10KWh to heat by 45 degrees. That is the total output from a PV on a good day in spring or autumn, I just checked the reading on my system and 4.7KWh. In Winter when you actually want hot water, my system generates around 1KWh so negligible difference to a small tank of water.
Ask them how they prevent pigeons nesting under them. My neighbours were not popular when the flying rats decided that solar panels made great shelters for the nests.
Yout neighbour needs to get their installation checked, mine has a few cm of space, any more and I think you would potentially have problems with wind getting under the panels and trying to lift them off the roof.
It you are talking rack mounted UPS designed to allow servers to do a graceful shutdown, you are talking 15 to 20 minutes of run time for a couple of servers. They would have a fit trying to power a house.
My installation.. Isn't normal, but check out APC's PX and MX systems. Mine's 1600kVA. Which still isn't ideal for powering a house, but helps demonstrate the cost/futility of 'renewable' power. And moreso 'grid scale' energy storage..
Strange thinking, I am pretty certain that people don't want hot water in the event of a power outage, they want electricity.
So you have a modern home with a condensing boiler, solar panels and radiators. You have a power cut. Your solar panels can't power your boiler, so your radiators go cold..
Again, what use is hot water in the event of power failure ? Or even for storing 'excess' power. Why do thing people use combi-boilers ?
John Prescott and industry lobbying. You're kinda asking 'What use is heating in the event of a power failure' given many homes rely on hot water for heating.
All studies show that for most domestic systems, heating up water as and when needed it much more useful then heating up loads and storing it. That is why you get cold feed only appliances these days, its more efficient.
Depends how you measure efficiency. So a solar PV system in a power cut is zero efficiency, even though it may still be generating power. At night, it's also zero efficiency. During the day it may be very low efficiency if all it's doing is exporting power. So heating water can be more efficient, or even just pre-heating it via PV or thermal. There can also be some myths around inefficiency of hot water tanks. If they're leaking heat into a home, that's heat heating the home which doesn't need you to burn more gas etc.
I think you SEVERELY overestimate how much excess power a domestic PV system is generating. A 180 litre hot water tank (a small one) would take around 10KWh to heat by 45 degrees. That is the total output from a PV on a good day in spring or autumn, I just checked the reading on my system and 4.7KWh. In Winter when you actually want hot water, my system generates around 1KWh so negligible difference to a small tank of water.
Nope, that just demonstrates how futile the 'renewables' industry can be. We've 'invested' billions in creating something that generates electricity, except at night or in a power cut and very little power in winter when there's peak heating demand. And given domestic heating/cooking accounts for around 25% of CO2 emissions, gas will have to be banned in homes to hit our carbon reduction targets..
And then of course people think they'll be able to recharge their electric cars via solar panels..
Or even real. Didn't we establish in another thread that it was merely a fantasy, along with your cunning plans to convert Eel Towers to DC, and game the Economy 7 tariff by storing off-peak energy and using it later?
So really your contributions to this thread are just another opportunity for you to attack renewable energy.
Or even real. Didn't we establish in another thread that it was merely a fantasy, along with your cunning plans to convert Eel Towers to DC, and game the Economy 7 tariff by storing off-peak energy and using it later?
So really your contributions to this thread are just another opportunity for you to attack renewable energy.
So really your contributions to this thread are just another opportunity for you to attack renewable energy.
Nope, but then that was a couple of years ago. Since then you've learned nothing and others have learned that solar power doesn't work in a power cut (if you go with a 'standard' install). And in winter...
In Winter when you actually want hot water, my system generates around 1KWh so negligible difference to a small tank of water.
..couldn't even boil a kettle. But of course that depends on where you are, what panels you have and what area you can cover. But this is what happens when you give the double glazing industry something new to sell. It frequently gets mis-sold.
The 'renewables' industry is designed around generating subsidies.
Nope [... pile of fatuous verbiage confirming that the answer is in fact "yes"...]
It is still a fantasy though, isn't it, your "UPS"? You remember, the one whose most basic specifications you didn't understand and which in any case turned out to need a 3-phase AC supply? It either doesn't exist, or it isn't connected to anything, and still lies festering in your garage with the batteries continuing to deteriorate.
And that DC conversion project. That was a fantasy too. Did it even have a rationale?
Nope, but then that was a couple of years ago. Since then you've learned nothing and others have learned that solar power doesn't work in a power cut (if you go with a 'standard' install). And in winter...
In Winter when you actually want hot water, my system generates around 1KWh so negligible difference to a small tank of water.
..couldn't even boil a kettle. But of course that depends on where you are, what panels you have and what area you can cover.
I have no idea what you are saying, are you agreeing, disagreeing, what ?
As I said, using excess power to heat water is pointless in the grand scheme of things.
It is still a fantasy though, isn't it, your "UPS"?
It seems to be your fantasy. After all it's brought you out from under your bridge..
You remember, the one whose most basic specifications you didn't understand and which in any case turned out to need a 3-phase AC supply?
Nope. It would be the one where you missed the 3-phase bit when I originally cited the specs. And instead got yourself very confused about online/inline/offline operation and basic power switching technology.
Hot water cylinders and inverters make a much simpler 'UPS' though. See also-
Heating water using a wind turbine is one of the most efficient uses of that renewable resource. When a wind turbine is used to charge a battery bank a lot of power is wasted in heat in the coils of the turbine alternator etc. particularly during gusty conditions. When the turbine is instead used to heat water with a suitably rated immersion heater element, virtually every watt that is generated heats water, even when the turbine is only turning slowly. For every degree the water is heated in this way, electricity or gas (and therefore money) which would otherwise have been used to raise the water temperature is saved.
Same principle would apply to solar. But you and c4rv seem to think this is a bad idea. It is of course a better idea than making constraint payments to windfarm operators when there's a demand imbalance, or wasting billions more trying to get grid-scale energy storage working.
It either doesn't exist, or it isn't connected to anything
That's just your brain..
And that DC conversion project. That was a fantasy too. Did it even have a rationale?
Usual efficiency one. If you're producing DC, converting to AC and back wastes energy and can add costs.
I have no idea what you are saying, are you agreeing, disagreeing, what ?
I'm saying it's one of those things where people have to do their homework carefully. Solar isn't an energy miracle and 'free' solar can work out expensive depending on people's usage patterns.
As I said, using excess power to heat water is pointless in the grand scheme of things.
Again that depends on system design. If you've got a house where you can use hot water it can make sense. Especially if daytime usage is normally low. That kind of ignores the subsidies though, but that depends on whether people are interesting in making/using energy, or subsidies.
If they're simply chasing subsidies then the economics can work against them. So subsidies are paid by the home owners either from their tax or from charges added to their energy bill. The more 'renewables' that are installed, the more those subsidies cost and the higher bills will get. Solar is out of line with normal peak demands, so peak energy will get even more expensive. And as that's in the evening, most of the year solar panels won't help.
Then there's the challenge of meeting our decarbonisation targets, which means that domestic heating will have to switch from gas to electricity. So long term, using 'free' energy to heat water could make even more sense..
Nope. It would be the one where you missed the 3-phase bit when I originally cited the specs.
I doubt it. I remember waiting for your explanation of how you were going to get a 3-phase Economy 7 tariff, or simulate one from your single-phase supply. All so you could end up paying more for your electricity. It never arrived.
And instead got yourself very confused about online/inline/offline operation and basic power switching technology.
No, that was you again. It's always you. You, after all, are the man who can't even understand logarithms, let alone electrical engineering.
Usual efficiency one. If you're producing DC, converting to AC and back wastes energy and can add costs.
So talk me through which appliances (in your fantasy, which I'll continue to indulge) you were planning to convert to DC. Perhaps we can assess the likely gains.
Though quite why a man who had entirely missed the point about Faraday efficiency and other losses in his fantasy UPS would be worrying about energy efficiency is a bit of a mystery.
..would be worrying about energy efficiency is a bit of a mystery.
Oh dear. You've escaped from under your bridge. So wrt efficiency, don't you think there's something odd about generating your own power that doesn't work (in many installations) when there's an external power cut?
So wrt efficiency, don't you think there's something odd about generating your own power that doesn't work (in many installations) when there's an external power cut?
It's not ideal. But doing it differently would incur considerable additional complexity and cost. What we want is a reliable grid.
So, your fantasy DC conversions. Which appliances?
But doing it differently would incur considerable additional complexity and cost.
Why? It's just an isolation requirement and it's already built into standard invertors. Just in a very dumb way so you can't use your solar panels in a power cut. It adds cost, but it's hardly complex to stick an isolator your side of the meter.
What we want is a reliable grid.
And you really think feeding variable quality power into a distribution grid that was never designed for this makes it more reliable?
Or in another word: 'do'. Since if you have the money for the initial outlay and the conditions are right, it's potentially a decent investement for a longterm home.
Having your supply isolated in the event of a power cut is..
It's also a load-matching requirement. Isolation is the easy bit.
Only a few posts ago you told me it was complex and expensive. Now you're saying it's easy? I'm getting a sense of deja vu.
So why would load-matching into a heating element be difficult, or expensive?
It's one of the challenges. The grid has to adapt.
Why? So solar panels that can't even boil a kettle can carry on generating subsidies for 'free' panel installers? If it's the solar industry creating the instability, then surely it should pay the costs.. But then the industry would be even less economically viable than it is now.
Only a few posts ago you told me it was complex and expensive. Now you're saying it's easy? I'm getting a sense of deja vu.
Whereas I am getting the sense of you never understanding anything you read. Again.
So why would load-matching into a heating element be difficult, or expensive?
Yes, because that's exactly what people want in the event of a power cut: a marginally warmer hot water tank. Hasn't another poster already explained this to you?
Yes, because that's exactly what people want in the event of a power cut: a marginally warmer hot water tank. Hasn't another poster already explained this to you?
It's just a simple & cheap use for solar energy. Whether that's a benefit depends on the OP or any other person's energy usage patterns.
But basically what's been established is..
In the event of a power cut, your £8-10,000 elecricity generation becomes a roof ornament.
During winter, unless you've got a lot of panels, they can't boil a kettle anyway..
You don't understand how isolators or invertors work. It might be 1,000V+ DC panel side, but it should be 240V-ish the other side. Amps of course will vary, so for the power to be of any use, you need something that can deal with 'dirty' power.. And modern living has no requirement for hot/warm water.
Then for 'free' installations, there are payback problems based on usage patterns, ie if you don't export enough power, the panels won't pay for themselves. And if subsidy rates change, they won't either.
And we're going to have to spend billions on grid upgrades to support these wonders of modern living, but the people who have them don't think they're going to be paying these costs.
It's just a simple & cheap use for solar energy. Whether that's a benefit depends on the OP or any other person's energy usage patterns.
So additional complexity and cost for almost no benefit, even under the rare condition of a power outage. Sounds like the kind of thing you would like.
You don't understand how isolators or invertors work.
If there is a lack of understanding to be had, you can always be relied upon to be the one having it.
Anyway, you were about to hold us enthralled with details of the appliances you claim to be converting to DC. Must have just slipped your mind in all the excitement!
Comments
If anything, the only potential issue (round here) is seagulls using the v-shape crevice at the very top to possibly build a nest in. But it hasn't happened yet, perhaps they find the panels too shiny/hot, although they do perch on the top edge occasionally.
It need not get that complex, but problem is current systems are designed around generating subsidies, not electricity. A generator that you can't use in a power cut is dumb in only the way 'Green' power systems can manage..
Well.. I have UPS, as in large rack previously intended for a datacentre. And am in the process of converting stuff to run off DC.. which is something of a larger project. But if we were really serious about energy efficiency would be built into new builds.
(One challenge for new homes is having any space for a decent sized hot water tank. Perception is this is 'energy inefficient'. Go figure.)
This is where a nice load of water helps. It's the cheapest form of 'renewable' energy store given the cost of storage tanks, and heating elements also being dirt cheap, low maintenance and not very fussy about power quality.. Rather than 'modern' homes with solar power, condensing boilers and no heat, hot water or power in a power cut. How does that make any sense?
Another issue is appliances. So you're potentially getting 'free' hot water. What do you then use it for if you've got an electric shower, and washing machine/dishwasher that only has a cold water inlet? But that again is a lack of joined-up thinking from industry.
I think it's very feasible with hot water acting as your 'UPS'. It's just a heat store instead of an electricity store. Otherwise you're right and we really need to do more work on better/cheaper ways to utilise 'dirty' power.. Otherwise many of these 'Green' initiatives are really a waste of time, money and of course energy.
It you are talking rack mounted UPS designed to allow servers to do a graceful shutdown, you are talking 15 to 20 minutes of run time for a couple of servers. They would have a fit trying to power a house.
Strange thinking, I am pretty certain that people don't want hot water in the event of a power outage, they want electricity.
Again, what use is hot water in the event of power failure ? Or even for storing 'excess' power. Why do thing people use combi-boilers ? All studies show that for most domestic systems, heating up water as and when needed it much more useful then heating up loads and storing it. That is why you get cold feed only appliances these days, its more efficient.
I think you SEVERELY overestimate how much excess power a domestic PV system is generating. A 180 litre hot water tank (a small one) would take around 10KWh to heat by 45 degrees. That is the total output from a PV on a good day in spring or autumn, I just checked the reading on my system and 4.7KWh. In Winter when you actually want hot water, my system generates around 1KWh so negligible difference to a small tank of water.
Yout neighbour needs to get their installation checked, mine has a few cm of space, any more and I think you would potentially have problems with wind getting under the panels and trying to lift them off the roof.
My installation.. Isn't normal, but check out APC's PX and MX systems. Mine's 1600kVA. Which still isn't ideal for powering a house, but helps demonstrate the cost/futility of 'renewable' power. And moreso 'grid scale' energy storage..
So you have a modern home with a condensing boiler, solar panels and radiators. You have a power cut. Your solar panels can't power your boiler, so your radiators go cold..
John Prescott and industry lobbying. You're kinda asking 'What use is heating in the event of a power failure' given many homes rely on hot water for heating.
Depends how you measure efficiency. So a solar PV system in a power cut is zero efficiency, even though it may still be generating power. At night, it's also zero efficiency. During the day it may be very low efficiency if all it's doing is exporting power. So heating water can be more efficient, or even just pre-heating it via PV or thermal. There can also be some myths around inefficiency of hot water tanks. If they're leaking heat into a home, that's heat heating the home which doesn't need you to burn more gas etc.
Nope, that just demonstrates how futile the 'renewables' industry can be. We've 'invested' billions in creating something that generates electricity, except at night or in a power cut and very little power in winter when there's peak heating demand. And given domestic heating/cooking accounts for around 25% of CO2 emissions, gas will have to be banned in homes to hit our carbon reduction targets..
And then of course people think they'll be able to recharge their electric cars via solar panels..
So really your contributions to this thread are just another opportunity for you to attack renewable energy.
That explain the nonsense that he is spouting.
Nope, but then that was a couple of years ago. Since then you've learned nothing and others have learned that solar power doesn't work in a power cut (if you go with a 'standard' install). And in winter...
In Winter when you actually want hot water, my system generates around 1KWh so negligible difference to a small tank of water.
..couldn't even boil a kettle. But of course that depends on where you are, what panels you have and what area you can cover. But this is what happens when you give the double glazing industry something new to sell. It frequently gets mis-sold.
The 'renewables' industry is designed around generating subsidies.
And that DC conversion project. That was a fantasy too. Did it even have a rationale?
I have no idea what you are saying, are you agreeing, disagreeing, what ?
As I said, using excess power to heat water is pointless in the grand scheme of things.
It seems to be your fantasy. After all it's brought you out from under your bridge..
Nope. It would be the one where you missed the 3-phase bit when I originally cited the specs. And instead got yourself very confused about online/inline/offline operation and basic power switching technology.
Hot water cylinders and inverters make a much simpler 'UPS' though. See also-
http://www.reuk.co.uk/200W-12V-Immersion-Heater.htm
Heating water using a wind turbine is one of the most efficient uses of that renewable resource. When a wind turbine is used to charge a battery bank a lot of power is wasted in heat in the coils of the turbine alternator etc. particularly during gusty conditions. When the turbine is instead used to heat water with a suitably rated immersion heater element, virtually every watt that is generated heats water, even when the turbine is only turning slowly. For every degree the water is heated in this way, electricity or gas (and therefore money) which would otherwise have been used to raise the water temperature is saved.
Same principle would apply to solar. But you and c4rv seem to think this is a bad idea. It is of course a better idea than making constraint payments to windfarm operators when there's a demand imbalance, or wasting billions more trying to get grid-scale energy storage working.
That's just your brain..
Usual efficiency one. If you're producing DC, converting to AC and back wastes energy and can add costs.
I'm saying it's one of those things where people have to do their homework carefully. Solar isn't an energy miracle and 'free' solar can work out expensive depending on people's usage patterns.
Again that depends on system design. If you've got a house where you can use hot water it can make sense. Especially if daytime usage is normally low. That kind of ignores the subsidies though, but that depends on whether people are interesting in making/using energy, or subsidies.
If they're simply chasing subsidies then the economics can work against them. So subsidies are paid by the home owners either from their tax or from charges added to their energy bill. The more 'renewables' that are installed, the more those subsidies cost and the higher bills will get. Solar is out of line with normal peak demands, so peak energy will get even more expensive. And as that's in the evening, most of the year solar panels won't help.
Then there's the challenge of meeting our decarbonisation targets, which means that domestic heating will have to switch from gas to electricity. So long term, using 'free' energy to heat water could make even more sense..
No, that was you again. It's always you. You, after all, are the man who can't even understand logarithms, let alone electrical engineering.
So talk me through which appliances (in your fantasy, which I'll continue to indulge) you were planning to convert to DC. Perhaps we can assess the likely gains.
Though quite why a man who had entirely missed the point about Faraday efficiency and other losses in his fantasy UPS would be worrying about energy efficiency is a bit of a mystery.
Oh dear. You've escaped from under your bridge. So wrt efficiency, don't you think there's something odd about generating your own power that doesn't work (in many installations) when there's an external power cut?
So, your fantasy DC conversions. Which appliances?
Why? It's just an isolation requirement and it's already built into standard invertors. Just in a very dumb way so you can't use your solar panels in a power cut. It adds cost, but it's hardly complex to stick an isolator your side of the meter.
And you really think feeding variable quality power into a distribution grid that was never designed for this makes it more reliable?
It's one of the challenges. The grid has to adapt.
Having your supply isolated in the event of a power cut is..
Only a few posts ago you told me it was complex and expensive. Now you're saying it's easy? I'm getting a sense of deja vu.
So why would load-matching into a heating element be difficult, or expensive?
Why? So solar panels that can't even boil a kettle can carry on generating subsidies for 'free' panel installers? If it's the solar industry creating the instability, then surely it should pay the costs.. But then the industry would be even less economically viable than it is now.
Yes, because that's exactly what people want in the event of a power cut: a marginally warmer hot water tank. Hasn't another poster already explained this to you?
It's just a simple & cheap use for solar energy. Whether that's a benefit depends on the OP or any other person's energy usage patterns.
But basically what's been established is..
In the event of a power cut, your £8-10,000 elecricity generation becomes a roof ornament.
During winter, unless you've got a lot of panels, they can't boil a kettle anyway..
You don't understand how isolators or invertors work. It might be 1,000V+ DC panel side, but it should be 240V-ish the other side. Amps of course will vary, so for the power to be of any use, you need something that can deal with 'dirty' power.. And modern living has no requirement for hot/warm water.
Then for 'free' installations, there are payback problems based on usage patterns, ie if you don't export enough power, the panels won't pay for themselves. And if subsidy rates change, they won't either.
And we're going to have to spend billions on grid upgrades to support these wonders of modern living, but the people who have them don't think they're going to be paying these costs.
If there is a lack of understanding to be had, you can always be relied upon to be the one having it.
Anyway, you were about to hold us enthralled with details of the appliances you claim to be converting to DC. Must have just slipped your mind in all the excitement!
Yes, that would seem to sum up most solar installations and renewables in general.