Anyone done solar energy conversions in their home?

[Fuzz]

Due to the ever increasing cost of leccy and gas it was decided at the beginning of the year to try and get this property more efficient.
We started by empting all the crap out of the loft and installing fresh 200mm of insulation (already had 50mm but it was 36 years old and compacted by the aforementioned crapola)
Turned out that it could be installed and fitted FREE due to mothers age woot!
So that concluded it was noticed a rise of at least a couple of degrees C in the room temps. RESULT

Next it was decided to try and cut down on water heating costs and that's where I am at at the moment having just shown the sales rep from a company called Solar - UK out of the door.

A couple of weeks back we had a flyer through the door about said company and so we sent it back.
Fair enough he demo'd his companies products very well but used the term "if you sign tonight yada yada, you can save £4500 pounds
Total installed price if I signed tonight was £11600
Instantly this put my back up and when it was obvious I wanted to investigate things further he started with "I don't do this to sit here for 2. 1/2 hrs wasting my time on people who don't believe what I say.
At that point I was like WTF, oh just GTFO (thinking it not saying it.. ) If you have faith in your product you don't need to try the hard sell approach tactic and I am the worst person to try that on, as I've been in front of you guys with your pie charts and spreadsheets before, saying how your product will save the world.. anyway, I digress..

Oh before I finish, I just found a "kit" on that auction site offering the same level of equipment, minus the install obviously, for £1095 quid. LOL

Basically my questions are as the title,
I'd like to hear about your installs,
what type it was,
whether you feel it was worth doing or not,
References of where to look for products on a DIY basis
Whether companies tried it on or ones you found really helpful.
Maybe stimulate some ideas of others doing the same if the ideas and solutions are sound.
Create an awareness of being green not for greens sake but to help utilise energy for free and save you a bit of cash.

This project suggests a recoup of initial outlay in the region of 5-6 years, this is based on a 20% rise in utility costs pr year using this particular system of vacuum tube solar (radiation not light) energy.

Your thoughts

 

[Deleted member 651465]

My brother has a solar panel fitted that heats his hot water.

(Looks like a metallic radiator on his roof)

Works very well, even on days where it's clouded over

 

[Greebo]

You should only do it for the environment, not for money saving as there won't be any with a bought system unless you buy a kit and all the install yourself in which case you might see a gain in about 15-20 years (assuming energy costs remain static and don't increase)

I have looked in depth at both solar panels and electric generating windmills.

Both have a payback longer than the lifespan of the equipment (based on fully installed syetms, not DIY) eg you will need to replace both before you have saved enough money to cover the initial cost.

It it generally accepted that the money is better spent of superior heat insulation eg loft (building regs now state that 400mm is the minimum for new houses), cavity wall insulation, energy efficient boilers or replacement glazing with K glass (over 20% of heat loss from a house is through the closed windows). All of those will give you a quicker payback on your original investment over solar or wind turbines.

Not evacuated solar panels can only heat your hot water for washing use, not your central heating system no matter what a saleman might say.

ALso not that if your boiler is a combi then this will need to be changed as well for the solar panel to work.

Evacuated solar panels and electric solar panels generate ideally (subject to location and sunshine) about 1000kwh per annum so a maximum of approximately £100 per annum saving (subject to you needing to use that much hot water in the first place. With a lifespan of 30 years you need to ensure that you do not spend more than £3000 fully installed. If less, then you can save money eventually.

Here's a useful list of things you can do to save money which a lot have a financial payback of only a year or two. Note that with you mother's age, you can get a lot of them with grants to decrease the payback time even further.

http://www.ecofreak.co.uk/cheaper-utility-bills.html

There's another very good site about solar heating which I can't locate again at the momemt which explains the full realistic benefits of solar panel heating and electric which is a green environmental site and they state that you won;t save any money, but you should still do it for the enviroment.

 

[Fuzz]

You should only do it for the environment, not for money saving as there won't be any with a bought system unless you buy a kit and all the install yourself in which case you might see a gain in about 15-20 years (assuming energy costs remain static and don't increase)

I have looked in depth at both solar panels and electric generating windmills.

Both have a payback longer than the lifespan of the equipment (based on fully installed syetms, not DIY) eg you will need to replace both before you have saved enough money to cover the initial cost.

This project suggests a recoup of initial outlay in the region of 5-6 years, this is based on a 20% rise in utility costs pr year using this particular system of vacuum tube solar (radiation not light) energy.

Going on other companies estimates I can get this outlay down to about £3500+vat fitted and installed... by someone more reputable than the salesman I had round.

Ignore the rest of this post, I have run out of time to finish off what I wanted to write so will come back to it later.

The energy necessary to heat water is determined by the specific heat of water:
cwater = 1 calorie/gm °C = 4186 J/kg°C = 1 BTU/lb °F

A typical U.S. residential water heater will be taken as one which has a capacity of 40 U.S. gallons (= 320 pounds, 145 kg, 151 liters). The typical heating range will be taken to be from 60 °F to 140 °F (15.6 °C to 60 °C). The energy required to heat the water can be determined from the specific heat relationship.
Q = cmΔT

The energy required to heat one tank of water over the specified range is then

(1 BTU/lb °F)(320 lb)(140°F - 60 °F) = 25,600 BTU

or

(4186 J/kg°C)(145 kg)(60 °C - 15.6 °C) = 26.9 million Joules

Since a kilowatt-hour is 3.6 million Joules, this energy amounts to about 7.5 kWh of electricity. Taking an electric energy cost of 9.5¢/kWh, it would cost about 71¢ to heat one tank of hot water with an electric hot water heater assuming all the electric energy went into heating the water.

Igno

 

[AHarvey]

It is something I am very interested in and will be looking at over the next year.

We've been in our house for 2 years and this winter it has been quite cold even with the heating on so I will be looking at insulation first.

Cavity wall and decent thick curtains for windows and doors.

The attic already has some but we were told when we moved in that there wasn't enough, so I will be leaving what is there an insulating the actual roof panels and then MDF'ing it throughout for storage.

I've got to look at the air vents out the back as we have raised flooring downstairs which isn't great.

I've a few books on solar experiments etc so over the spring I will be looking at experimenting with homemade panels etc and look at working out some decent systems for hot water & heating to see if I can come up with something cheap and reliable!

 

[Skull]

I don't see the point of doing it in the UK :S

Unless you can get solar panels for dirt cheap, the savings you'll make from the pathetic levels of sunshine here aren't going to pay for the panels for decades.

Sure, do it in a country that has near enough constant sunshine, you could probably power your whole house on that level of sunshine, then it might be worth it, but for the UK? I think the SOLAR part should be the big clue... Sun. Sunshine. Something we don't have for 8 months of the year.

 

[Fuzz]

I think this is in part the perspective of most people, but on reading about it (I thought the same) it would appear the more efficient evacuated tube type doesn't use sun LIGHT as such, it uses sun ENERGY.. different thing.
Radiation travels through the cloud cover fairly well therefore doesn't matter so much if it's not a bright day in the UK.
So unless it's raining and the cloud cover is really intense there can still be considerable benefit to keeping the water temps topped up in the airing cupboard tank.

 

[Skull]

I think this is in part the perspective of most people, but on reading about it (I thought the same) it would appear the more efficient evacuated tube type doesn't use sun LIGHT as such, it uses sun ENERGY.. different thing.
Radiation travels through the cloud cover fairly well therefore doesn't matter so much if it's not a bright day in the UK.
So unless it's raining and the cloud cover is really intense there can still be considerable benefit to keeping the water temps topped up in the airing cupboard tank.

About half as much electricity can be produced on cloudy days but if you are only trying to run one appliance (for example, your hot water heater), this is probably adequate voltage. On a very dark, gloomy day the solar cells may produce only about five to ten percent of the power they would normally create

So yes, using free energy from the sun to run your water heater is good, but if you're paying £5,000-£10,000 to do it then it's just not worth it.

If we had a lot of sunlight it would be much more worthwhile.

 

[AHarvey]

seen lots of experiments using homemade containers, black rubber surrounds, perspex fronts with heating elements from fridge freezers.

If you have the knowledge you could probably make a semi decent setup for heating water for washing etc.

Obviously heating a house is going to be a lot more complex

 

[norm]

I don't see the point of doing it in the UK :S

Unless you can get solar panels for dirt cheap, the savings you'll make from the pathetic levels of sunshine here aren't going to pay for the panels for decades.

Sure, do it in a country that has near enough constant sunshine, you could probably power your whole house on that level of sunshine, then it might be worth it, but for the UK? I think the SOLAR part should be the big clue... Sun. Sunshine. Something we don't have for 8 months of the year.

The panels will still generate energy on overcast days, albeit not as much. But solar panel technology is likely to become a lot more efficient within the next decade, thus making it more cost effective. And with the increasing popularity of solar cells it should lower costs through mass production.

 

[Fuzz]

So yes, using free energy from the sun to run your water heater is good, but if you're paying £5,000-£10,000 to do it then it's just not worth it.

If we had a lot of sunlight it would be much more worthwhile.

Who were you quoting there, whoever it was missed the point entirely..

you don't create electricity from the evacuated tube type solar panels, you heat Glycol (or some other low freezing point liquid) and shunt it around a system with a pump so that it acts as a heat coil in the bottom of the water tank in the airing cupboard.

It's just tubes with copper pipes and a bit of glass trickery thrown in with the tube design so the cost is nowhere near the 10's of thousands quoted above.
The roof pack tube block wont be more than a grand and a half ish.. Al you need then is some pipe to transfer it to the tank, a new tank with the coil in the bottom, not in the middle (stupid idea but safety issue) s pump to move it about and a control panel / temp monitors to tell it when to move the fluid.

 

[Skull]

Who were you quoting there, whoever it was missed the point entirely..

you don't create electricity from the evacuated tube type solar panels, you heat Glycol (or some other low freezing point liquid) and shunt it around a system with a pump so that it acts as a heat coil in the bottom of the water tank in the airing cupboard.

It's just tubes with copper pipes and a bit of glass trickery thrown in with the tube design so the cost is nowhere near the 10's of thousands quoted above.
The roof pack tube block wont be more than a grand and a half ish.. Al you need then is some pipe to transfer it to the tank, a new tank with the coil in the bottom, not in the middle (stupid idea but safety issue) s pump to move it about and a control panel / temp monitors to tell it when to move the fluid.

I've not been talking to those tube type panels, I was referring to ones that actually generate electricity themselves.