solar panels - anyone know much about them?
Discussion
I did some calculations a while ago (though leccie prices were lower) and by the time I'd got back the cost of purchase the units would have been thrown away about 1 year previously..... They were for PV cells. They also appear to be made using NC and that is not environmentally friendly to dispose of. I had a chat with a fellow who came to the door flogging them and he wasn't sure what his were made of, so it is possible that newer ones are not going to be killing the earth and can be safely disposed....But whether they are cost effective is another matter (Oh, and the calcs were done being quite generous with solar activity as well)
We looked at them at my work, it worked out to take about 100+ years for them to pay for themselves & off set the effect of making them.
Complete waste of time, BUT as someone else said the water ones are i hear rather good (simpler technology & saves you fuel costs due to water being already warm when it goes through your boiler so it uses less energy to heat it)
Complete waste of time, BUT as someone else said the water ones are i hear rather good (simpler technology & saves you fuel costs due to water being already warm when it goes through your boiler so it uses less energy to heat it)
I do this gear at work. In Edinburgh with average sunlight and current leccie prices the photovoltaic system (with 25 years warranty on all parts) returns your money in 56 years.
But prices will go up and there will be more sun later in life so id say about 40 years.
Add to that how much extra value that gets put onto your house id say it was an investment.
But prices will go up and there will be more sun later in life so id say about 40 years.
Add to that how much extra value that gets put onto your house id say it was an investment.
We have fitted PV to some of our units and much that I like the idea the payback is very poor at >35yrs. Mortgage lenders will not value properties up for them so really a waste of money.
If prices for electricty rise hugely in the future the supply and demand will bring solar PV prices right down, abit like double glazing.
At this point in time I would say don't waste your money.
Solar thermal are cheaper but the returns are harder to substantiate however they may eb worth considering especially if your water is heated by electricity.
If prices for electricty rise hugely in the future the supply and demand will bring solar PV prices right down, abit like double glazing.
At this point in time I would say don't waste your money.
Solar thermal are cheaper but the returns are harder to substantiate however they may eb worth considering especially if your water is heated by electricity.
We looked into the idea of fitting the water heater ones. But the problem is, in general we tend to use a lot of hot water in the mornings for showers. So whilst the first person may get some hot water that was heated the previous day, the next person's water will have to be heated by conventional means.
Heating water doesn't actually cost much, it's the central heating which uses lots of gas.
I couldn't really justify the cost of having it installed. It'd take years to see any benefit.
Solar power panels are pretty pointless unless you can convert your light bulbs to LED's and run them directly from the battery at 12 or 24 volts.
Heating water doesn't actually cost much, it's the central heating which uses lots of gas.
I couldn't really justify the cost of having it installed. It'd take years to see any benefit.
Solar power panels are pretty pointless unless you can convert your light bulbs to LED's and run them directly from the battery at 12 or 24 volts.
Plotloss said:
The ones that generate electricity are largely a white elephant.
The ones that heat water however are a different matter.
Very true.The ones that heat water however are a different matter.
The Photo Voltaic electric solar panels come in two flavours - monocrystaline and polycrystaline. These mono's are the most efficient panels but they will not give you a return on your money before 20 years which is when the warranty runs out! The hot water types are excellent and there are two types again; you want evacuated tube type not plate type as our climate here it not hot enough.
I spent a tad under £18k 5 years ago on a 3kw PV panel system, and a 24 tube evacuated system, but was turned down with planning permission by the local council because "the modifications to my roof line were not in keeping with the surrounding areas" I kid you not
5 years on and anything with a green label gets approved. I sold the system at quite a large profit to a guy in a remote part of Scotland that had no electricity to his farm! The PV system was 'grid-back' which means you actually feed home grown energy back into the national grid if you generate an excess of what you use. I had fifteen massive 200watt PV panels (2m tall x 1m wide) running through a Sunnyboy 3kw gridback meter. It is a false economy to use storage (leisure batteries) as they have a life at best of ten years, and the cost of the battery array would be about £3k so you would have to double my electricity output to warrant paying for them. That would be 30m2 of solar panels!There is a lot of snake oil in the industry, I am also a qualified sparky so I intended to fit all the equipment myself and get a grant, but when I investigated further, you can only buy an installation from an accredited installer. They would not let me use my own equipment. When I got quotes through from these various companies, their prices were double what I could source the equipment for, and the labour rate was also extortionate. So any grant would have been swallowed up in their markup and I could have fitted the same system myself for the same money without the grant. At the time it was one hurdle after the other, and I sold up after jumping through hoop after hoop. 5 years ago, they weren't as serious about it as they are now, so things should have changed. Two weeks ago I took a course to enable me to become a Commercial Energy Assessor as I think that the time is coming to get back in the business as I'm entrepreneurial, but I am going in with eyes and ears open and I am going to shop any dodgy practices I find through the correct channels this time.
There are noises that solar PV is going to come down in price dramatically in the next couple of years. A company in America has got a process where PV cells can be printed using fairly standard machinery. The results aren't as efficient as the expensive lab-built cells, but the costs are something like one tenth. We could see whole roofs being covered with this stuff.
As for solar thermal, the benefits can be pretty good, so long as you steer clear of the expensive end of the market. Navitron are the leaders here as has been pointed out.
You can combine solar with various other sources, and can get hot water in the morning. The important bit of technology here is a thermal store - basically a very large, well insulated hot water tank. It allows you to store up heat from any number of heat sources, then draw it off when you need it. Side benefits include mains pressure hot water with very high flow rates, and the ability to store up heat from sunny days and still use it when the sun goes in.
As for solar thermal, the benefits can be pretty good, so long as you steer clear of the expensive end of the market. Navitron are the leaders here as has been pointed out.
You can combine solar with various other sources, and can get hot water in the morning. The important bit of technology here is a thermal store - basically a very large, well insulated hot water tank. It allows you to store up heat from any number of heat sources, then draw it off when you need it. Side benefits include mains pressure hot water with very high flow rates, and the ability to store up heat from sunny days and still use it when the sun goes in.
We make them here, not in the section I work in though so I don't know much about them. What I do know is that we sell a lot of them to Southern Europe, they seem to be more effective/shorter payback time in sunnier climb's than ours. We have sold a lot to a company in Tenerife who have made a solar power station by putting 50,000 of them in a field!
The water ones do not heat water directly they use a glycol closed system.
The water ones for swimming pools heat the pool water directly.
Solar for electricity. There are new panels that are more efficient that are almost on the market (still too expensive, but getting close).
Payback after US Federal and State grants is 16 years, at current electic tarrifs, so 16 years or better.
In the States we can sell excess power back to electric company.The meter goes in reverse. In reality this is minimal due to size of the grants and basic economics.
In the event of a power outage you DO lose power as it is not healthy to have power feeding back on the line when a workman thinks it's dead
Although I would think it would be possible to use a changeover box similar to those used with emergency generators.
The water ones for swimming pools heat the pool water directly.
Solar for electricity. There are new panels that are more efficient that are almost on the market (still too expensive, but getting close).
Payback after US Federal and State grants is 16 years, at current electic tarrifs, so 16 years or better.
In the States we can sell excess power back to electric company.The meter goes in reverse. In reality this is minimal due to size of the grants and basic economics.
In the event of a power outage you DO lose power as it is not healthy to have power feeding back on the line when a workman thinks it's dead
Although I would think it would be possible to use a changeover box similar to those used with emergency generators.
They have them here in aus and even with the amount of clear sun we get they are not worth it. You get government grants for having them and you can get credits towards your energy bills if you put anything back in to the grid...but even with that I am told a 3KW system will take around 10 years to pay for itself and then you need to look at maintenance and replacement.
I'm also told that you cant really run anything off of them...the expensive things like electric ovens, heaters, air conditioners use more than the system can provide. You can apparently run your lights off of them but they are about the cheapest thing to run anyway!
Solar hot water is very popular here. We have it and as long as there is blue sky we never have to switch on the manual booster. Even first thing in the morning there is hot water for both of us to have a shower. Basically our hot water is free...but even then with only 2 of us our bills have never been particulary big anyway.
The system was already on the house when we moved in but I wouldnt have paid to put it in myself...Like I say with only 2 of us our bills have never been big enough to really justify this sort of stuff.
It amazes me how many people I talk to here that dont bother doing any real research, all they can see is the grant thinking they will get money in the bank and free energy!
I'm also told that you cant really run anything off of them...the expensive things like electric ovens, heaters, air conditioners use more than the system can provide. You can apparently run your lights off of them but they are about the cheapest thing to run anyway!
Solar hot water is very popular here. We have it and as long as there is blue sky we never have to switch on the manual booster. Even first thing in the morning there is hot water for both of us to have a shower. Basically our hot water is free...but even then with only 2 of us our bills have never been particulary big anyway.
The system was already on the house when we moved in but I wouldnt have paid to put it in myself...Like I say with only 2 of us our bills have never been big enough to really justify this sort of stuff.
It amazes me how many people I talk to here that dont bother doing any real research, all they can see is the grant thinking they will get money in the bank and free energy!
Slightly OT,
SS HSV said:
Two weeks ago I took a course to enable me to become a Commercial Energy Assessor as I think that the time is coming to get back in the business as I'm entrepreneurial, but I am going in with eyes and ears open and I am going to shop any dodgy practices I find through the correct channels this time.
What was involved in the CEA course? How much prior experience did it require you to have?The grant system has really screwed up the market here in the UK. You can get a grant if you buy from an accredited supplier, but the result is that accredited suppliers tend to put their prices up by about the value of the grant.
Solar thermal is fairly straightforward to plumb in, so it shouldn't need an expensive 'expert' to do the job. That said, you do need to know what you're doing and can't just bolt a couple of solar panels onto your existing plumbing if you want to get anything like a decent return. A qualified plumber should be able to do the job.
Solar hot water panels are as low as £250 from Navitron for a small one. You need to factor in a solar controller and probably a new hot water cylinder as well. A south facing roof is also quite important to an efficient system.
As for the flat panel v's tube arguments, the difference is fairly minimal in mild climates (ie. most of the UK). In the core winter months, tubes will capture more heat, but neither system will make a useful contribution to hot water so the benefit is next to non existent. During the summer months, both can produce the majority of your hot water if the system is sized correctly. Flat panels can be integrated with your roof, to look like a big skylight. Tubes are a bit more bulky, but can be more accurately aligned.
Solar thermal is fairly straightforward to plumb in, so it shouldn't need an expensive 'expert' to do the job. That said, you do need to know what you're doing and can't just bolt a couple of solar panels onto your existing plumbing if you want to get anything like a decent return. A qualified plumber should be able to do the job.
Solar hot water panels are as low as £250 from Navitron for a small one. You need to factor in a solar controller and probably a new hot water cylinder as well. A south facing roof is also quite important to an efficient system.
As for the flat panel v's tube arguments, the difference is fairly minimal in mild climates (ie. most of the UK). In the core winter months, tubes will capture more heat, but neither system will make a useful contribution to hot water so the benefit is next to non existent. During the summer months, both can produce the majority of your hot water if the system is sized correctly. Flat panels can be integrated with your roof, to look like a big skylight. Tubes are a bit more bulky, but can be more accurately aligned.
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