Should we install Solar Power?

Subject: Obit: Should we install Solar Power?
From: GUEST,beachcomber
Date: 09 Dec 06 - 04:37 AM

I can't seem to find a relevant debate in the Forum so am asking for opinion on the topic.
We are wondering if we should have a panel( or panels) installed on the south facing leaf of our roof as a means of heating for ourdomestic water supply. Radiators do not come into this.
We realise that it will not be efficient all year round in our Lattitude (Ireland) but would the installation work and resultant mess and clean-up be worth the aggravation?
Have any of the 'catters experience of this ?

Subject: RE: Obit: Should we install Solar Power?
From: Cats
Date: 09 Dec 06 - 08:18 AM

We have just had quotes for solar powered hot water system. We are in Cornwall, have SE facing roof which is not shaded at all and are going ahead with the order after Christmas. It is not expensive and we can get a grant towards it. The panels we are having put in are filled with glycol and are photosensitive so they work off light, not just sunlight. We also have solar panels for our campervan and our garden pond fountain. Definitley worth it, but do shop around.

Subject: RE: Should we install Solar Power?
From: Barry Finn
Date: 09 Dec 06 - 02:47 PM

Hi Beachcomber
Research about any grants, tax incentives, any special deals from your own power company or supplier, if there are any reseach programs or studies that will be a benint towards your doing this. I don't know what they're doing in Ireland to work towards pushimg energy saving but I do know here in the US it just keeps getting worst as far as any incentives go. It's almost like we're working backwards, opps, we are working backwards. I just bought a Totoya Prius, a Hybrid, & we can only get 1/2 the tax incentives that the government first offered & there doesn't look like they'll be any in 2007. Go firuge, & with all the screaming about the need for alternative energy sources.
Good Luck
Barry

Subject: RE: Should we install Solar Power?
From: Bert
Date: 09 Dec 06 - 11:50 PM

Yes.

Subject: RE: Should we install Solar Power?
From: Stilly River Sage
Date: 10 Dec 06 - 01:49 AM

Yes. And a friend who has done a lot of this himself says that the first thing you should do to get solid savings is solar hot water. So you're on the right track.

They've done remarkable things with solar power generation in Germany. You should research it. Many people give power back to the grid and realize a little income from it. And yet Germany isn't known as a sunny clime.

SRS

Subject: RE: Should we install Solar Power?
From: Megan L
Date: 10 Dec 06 - 06:36 AM

Beachcomber our uncle made his own solar panels which covered the whole of one side of the roof when he built his house almost 25 years ago now they provided most of the hot water he needed including a tick over for the radiator (Orkney scotland)

recently her reroofed and bought two small panels which do the same job as his early attempts

Subject: RE: Should we install Solar Power?
From: Cats
Date: 10 Dec 06 - 06:50 AM

I've just filled in the on line grant application form for solar heating and it took no more than 5 minutes. Go for it, but make sure your installer is registered with the solar heating registration body.

Subject: RE: Should we install Solar Power?
From: Black Beauty
Date: 10 Dec 06 - 07:10 AM

It's still very expensive even with grant aid.

Subject: RE: Should we install Solar Power?
From: autolycus
Date: 10 Dec 06 - 07:12 AM

Do British councils do it for us tenants in any circs.?






      Ivor

Subject: RE: Should we install Solar Power?
From: GUEST,beachcomber
Date: 10 Dec 06 - 10:03 AM

Many, many thanks all for the information and opinions supplied to this topic.
Yes, the Irish Government (awash with over subscribed taxes..or so they constantly inform us) have considerable Grant aid on offer to Solar Power Installers as well as for a range of other efficient and environmentally friendly energy sources.
Barry, The US Government's apparent lack of support for such projects is worrying, right enough.
In spite of Grants the installation cost would be expensive but, that needs to be offset against the future, hopefully reduced , water heating bills, right?

Subject: RE: Should we install Solar Power?
From: Genie
Date: 10 Dec 06 - 04:24 PM

Things are not likely to get better in the US as long as our government is dominated by politicians who are in bed with the oil and gas industries.


Are there good sites with tables to help you figure out the expected time till you break even and begin to see net savings?

Subject: RE: Should we install Solar Power?
From: artbrooks
Date: 10 Dec 06 - 04:52 PM

We looked into it when we moved to New Mexico (where the sun shines most of the time), and it would have cost several thousand dollars and would have taken 10-15 years before the break-even point, as far as hot water production alone is concerned. Since then, however, the local utility company has set up a scheme that lets you sell excess power generated to them, so it is now a much more plausable idea. Definitely look at a power generation and storage option as well as hot water.

Subject: RE: Should we install Solar Power?
From: Rowan
Date: 10 Dec 06 - 05:21 PM

Although Beachcomber was specific, in the original question, about solar heated water supply a few posters have introduced photovoltaic power generation as a topic. Coming from a place more endowed with sunshine (and thus less endowed with water) than Ireland, my experience may be of little help but, here goes.

New England (Australia) has a rather frosty winter (meaning very clear skies) and a warm summer. My house is constructed to allow passive solar heating, which means that there are a few weeks in winter where, what architects call "the comfort zone", extra heating is required. The hot water supply is a closed-cycle thermosiphoning solar panel, meaning that the glycol/water mix that circulates through the panel and the heat exchanger in the storage tank is isolated from the potable water. Open-cycle panels allow the potable water to pass through the solar panel and the experience here in winter is that deep frosts can burst the piping in the solar panel unless you drain it overnight. Extra plumbing (read "expense") and the chance of unexpected frosts causing damage and loss of precious water mean most people with solar hot water systems here use closed-cycle thermosiphoning solar panels.

Over the years I've averaged no more than a week of consecutive cloudy days, meaning that the water temperature (usually 80 degrees Celsius) will drop to 50 by the end of that time. The storage tank has an "Off peak" electric element that, if I switched it on, would automatically heat the water to 72 degrees Celsius; I don't bother. If I lived in a cloudier environment I'd probably consider a heat pump; electrically driven (and thus more expensive to run), these can extract heat from air at temperatures as low as about 5 degrees Clesius to heat air or water.

My father (in Adelaide, with a more "Mediterranean" climate according to the geographers) used a home made set of solar panels to heat his swimming pool. The piping was all "poly pipe" of the type used in agriculture (I think Americans call it ABS piping), with easy jointing, and mounted on the roof. Thermosiphoning won't work if the storage (the swimming pool) is below the panels (on the roof of the house) but the pump used for filtration and treatment of the pool water also pumped through the solar panel. He gave it to me to install in my house as a space-heater but I'm not installing it until I can reduce my power requirements.

Which brings me to photovoltaics. I have enough north-facing roof to install 40 odd square metres of such panels at the right angle (pun intended) to maximise efficiency but I have concerns about electrical storage; the batteries are special, expensive and not particularly friendly to either the OH&S nor the ecological environment. So I wait for the local electrical power suppliers (often called "No Power" in the past) to change their policy and accept people like me feeding excess supply into the grid and offsetting my bills.

In an Australian rural environment (read 'bushfires') distributed power sources across the network can be a problem. When the main grid is disconnected (accidentally, because of breaks in the line, or deliberately, to ensure safe working below the line in smoke that may allow arcing) you don't want the lines still alive because of characters like me still pumping power into the grid.

Sorry I know nothing about Irish tax incentives but the above may be helpful.

Cheers, Rowan

Subject: RE: Should we install Solar Power?
From: GUEST,CATS
Date: 11 Dec 06 - 04:27 AM

Black Beauty - I don't think that the price I have been quoted is expensive at all. For 75% of all hot water needs in a 4 bedroomed house, all parts, labour and VAT to install, less than £3500. That is much less than I thought it was going to be and I have had my grant application approved, so it will bring it down to about £3000.

Subject: RE: Should we install Solar Power?
From: Tom Hamilton frae Saltcoats Scotland
Date: 11 Dec 06 - 03:38 PM

aye

Subject: RE: Should we install Solar Power?
From: Amos
Date: 11 Dec 06 - 04:19 PM

We heated our water and our home using solar-thermal water systems in our first house, many years ago. It was quite efficient. The installation, including heating ducts, was all done by contractors and went relatively smoothly.

On photovoltaics, in San Diego you can supply all th eelectricity for an average family with about 1800 square feet of panels. The local energy company will supply you if you request with a modern meter that measures time-of-use, not just total kWH. They will then credit you with credit up to the amount of your bill for any surplus your meter shows flowed back into the grid from your system. You can end up being energy-neutral as to cost, or very nearly so, depending on how many panels you mount. You can mount them on the roof in a frame, or on poles, or in empty acreage in a frame or on poles. They ideally need to face south (in the Northern hemisphere). BUT a whole-house system can cost you 20,000 US. No small change, that. Some federal credits may also apply. Look to spend 8 to 10 years to pay it all back in saved electrical bills UNLESS rates rise significantly which is perfectly possible with oil costs accelerating.

If they do, your pay-back period goes down accordingly as your monthly savings goes up.

Plus you get the satisfaction of knowing you are off the grid and not burning oil to heat with.

A

A

Subject: RE: Should we install Solar Power?
From: Bugsy
Date: 12 Dec 06 - 02:36 AM

We've had solar hot water in our last 3 houses (we live downunder), and find that we need to use our booster maybe 2 months of the year. The rest of the time it's free hot water and piping hot at that.

Go for it!


Cheers


Bugsy

Subject: RE: Should we install Solar Power?
From: GUEST,beachcomber
Date: 12 Dec 06 - 04:04 PM

Thanks again all, in particular the positive postings. I'm going to go for it as you suggest Bugsy. Now I've just one other aspect of household heating to "air" but I will post it on a seperate thread soon.

Subject: RE: Should we install Solar Power?
From: Donuel
Date: 13 Dec 06 - 10:31 AM

I see no mention of maintenence costs ie battery replacements.

Subject: RE: Should we install Solar Power?
From: GUEST,Cats
Date: 13 Dec 06 - 11:24 AM

All my parts are guaranteed for 25 years. I can also have the excess power stored to run the battery.

Subject: RE: Should we install Solar Power?
From: GUEST,Jim Martin
Date: 13 Dec 06 - 09:32 PM

Rowan - your comment about not wanting to pump juice back into the grid when there may be work being carried out on it (safety implications!).

I believe with wind turbines, you have to have a piece of equipment called a grid tie inverter (cost: about €1,000) to prevent this happening, whether this applies with solar panels as well, I don't know. Sorry, not too well up on the technicalities!

Subject: RE: Should we install Solar Power?
From: Rowan
Date: 14 Dec 06 - 05:15 PM

Donuel
Things may have changed a bit but, when I was buidling my house and calculating costings, the total cost of connecting to the grid was $12k (these are Australian dollars) while installing photovoltaics sufficient to run an efficient (read "careful") household was $20k; subsidies only started once the cost exceeded $20k. While there was some ongoing cost regarding the panels the major such cost was maintenance and replacement of the special batteries, which had a 10 year life expectancy. So we went onto the grid.

As a person who'd lived (and run school camps) well away from the grid I was prepared for the constant 'situational awareness', both technically and temperamentally, required when you live where you need to cope with monitoring electrical supply, water supply etc. But my then partner had quite different strengths and found it difficult to come to terms with the relatively simple (to me) monitoring of the water level in the tank that collected from the roof and using the transfer pump (a 'firefighter' model) to transfer water to the storage/header tank up the hill.

I mention this because many photovoltaic systems require 'situational awareness' and consequent behaviour modification (not using the washing machine when you want to watch the telly is a minor example) and many people find it difficult to cope with the constant need to "think" about things that most of us take for granted. The best example for me was the behaviour of city people at the school camp I ran. Water only existed in the 9" between the tap and the plughole until they came to Steiglitz, where they found that water to make coffee and wash up in either came with wrigglers (mosquito larvae ) from the tanks of roof water or sediment (clay suspension) from the dam; if they didn't wait for the toilet cisterns to fill completely before flushing there wouldn't be enough flow to prevent them from becoming intimately familiar with the operations of a septic system.

All good fun and a great way of educating people about how we all should monitor the effects of our behaviour, constantly. But some find it a grind they want to leave behind them.

Jim Martin
You may well be right and it may well be that the electricity suppliers are using such argument as a way of dragging the chain; I don't know. For a while I lived a bit further west of where I now live and was in the very last house at the end of the last spur of the local power grid. If three people closer to the grid all turned on their kettles at the same time my power supply would cut out. At least, that was my hypothesis for the frequent morning power cuts and it got worse during shearing. Most domestic power supplies in Australia are 'split' into two, with electric hot water services connected (and metered) separately during "off peak" times in the wee small hours. The off peak connection at that house was switched by a 'clock' timer in the meter box and, because of the frequent power cuts was routinely delivering "off peak" power at times when there was peak load on the grid.

This was later fixed by replacing the clock timer with a pulse switcher; an HF pulse would be sent down the grid power lines to connect and disconnect the "off peak" domestic circuits. It struck me that distributed domestic power generators could be controlled by a similar mechanism, the theory being that domestic photovoltaics and turbines are connected to the grid by an isolating switch that only remains in the "connect" position while it receives an HF signal down the grid lines; when this signal drops out the isolating switch trips the generator out of the grid.

All photovoltaics generate DC (which needs to be inverted into AC) and turbines (the old Dunlites were DC but these days I suspect everything is AC) would all need their power 'conditioned' at the house before it's delivered into the grid so I suspect such an isolation mechanism could be part of the black box that does the conditioning. Should be a doddle!

Beachcomber
As they say in the classics, all power to your elbow!

Cheers, Rowan

Subject: RE: Should we install Solar Power?
From: Mr Happy
Date: 13 Jan 08 - 09:08 AM

Can solar panels pick up any useable charge from sources other than sunlight, like street lights?

Subject: RE: Should we install Solar Power?
From: The Fooles Troupe
Date: 13 Jan 08 - 09:41 AM

"Can solar panels pick up any useable charge from sources other than sunlight, like street lights?"

Depends on the level of incident light, and the design/capability of the PV panels. Sorta like - 'is this tune too fast for you?' :-P

Subject: RE: Should we install Solar Power?
From: Mr Happy
Date: 13 Jan 08 - 09:42 AM

Is that a yes or a no?

Subject: RE: Should we install Solar Power?
From: skarpi
Date: 13 Jan 08 - 10:43 AM

Should we install Solar Power? YES :>)

but not where the sun dont shine

Subject: RE: Should we install Solar Power?
From: Stilly River Sage
Date: 13 Jan 08 - 12:17 PM

I don't think so, Mr. Happy. A streetlight doesn't have any where near the power or density of the light to tickle those panels in a meaningful way. But I noticed an interesting event a few weeks ago that could have an impact, if you were lucky (or not) in your neighbors. There is a glass-sided building on the west side of town that can be seen from a rise closer to downtown. When you drive south toward this outer building at just the right time of day you're blinded by the sunlight reflected from all of that glass. That gave me the idea that you might be able to set up a mirror low enough that it wouldn't block your panels but that it could boost the amount of light hitting it. Or you could even go with a convex or concave mirror for some interesting effects. (Pity the neighbors of that reflective building--that light is enough to peel paint or kill plants with its brightness).

I don't know if there is any research into this, but I'm probably not the first to make this observation.

SRS

Subject: RE: Should we install Solar Power?
From: Cats
Date: 13 Jan 08 - 12:46 PM

If this helps at all, we installed a single solar panel last March and we have worked out that my oil bill has gone down by nearly £750 since then. At this rate it will pay for itself in less than 4 years, nowhere near the 8 years we were told.   Go for it.

Subject: RE: Should we install Solar Power?
From: dick greenhaus
Date: 13 Jan 08 - 01:53 PM

Re water heating-
first, figure out how much you currently spend on heating water. That's the theoretical upper limit on savings. Secondly, consider how you currently heat water; if you're not heating with electricity, you may end up losing money with a solar water heater--the backup for the solar panels is invariably an electric heater (low standby losses) which is damned expensive to run.

Photovoltaics make sense if you can get some government subsidies. We've installed photovoltaic panels here in New Jersey, but the state is very supportive in terms of subsidies and credits for power generated. Even so, it's only marginally cost-effective (but should be more so when electric rates go up, as they're bound to.)

Subject: RE: Should we install Solar Power?
From: katlaughing
Date: 13 Jan 08 - 05:23 PM

I see Europe is taking a look at Solar Treefor street lighting. Very pretty...I wouldn't mind having one near my house.:-)

Subject: RE: Should we install Solar Power?
From: katlaughing
Date: 13 Jan 08 - 05:29 PM

Found THIS on that same site. Rather interesting!

Subject: RE: Should we install Solar Power?
From: open mike
Date: 14 Jan 08 - 12:01 AM

If you have a system that has some fluid that does not freeze
easliy this will be better. I have had solar collectors that
freeze (water expands with enough force to burst copper pipes)
even when the temp is a bit ABOVE freezing, as the heat
dissapates (radiates) to the night sky making temps drop
inside the collector.

some units have a small low voltage pump (grundfos brand?)
to circulate the fluid, and some have a heat exchanger that

Subject: RE: Should we install Solar Power?
From: The PA
Date: 14 Jan 08 - 03:46 AM

We run the whole of our stable yard on solar power, lighting, sockets, electric fencing etc. Best thing we ever did.

Electricity company wanted £10,000 to connect us to a supply which already runs across one of our fields.

We would have had to dig a 1M deep 200yd trench lay the cable and do all the connections on the yard. All they would do would be to do the main connection at the other end (transformer box thingumy is already there).

The solar system is miles cheaper for us. Dont know about domestic dwellings though.

Subject: RE: Should we install Solar Power?
From: The Fooles Troupe
Date: 14 Jan 08 - 05:39 AM

"There is a glass-sided building on the west side of town that can be seen from a rise closer to downtown. When you drive south toward this outer building at just the right time of day you're blinded by the sunlight reflected from all of that glass. That gave me the idea that you might be able to set up a mirror low enough that it wouldn't block your panels but that it could boost the amount of light hitting it."

I tend to watch DW TV Magazine a lot - it turns up here on the Community TV Bris 31 - and they repeat it each day for a week...

A while ago - and it's most likely that was where I saw it - there was a mention of an Alps town at the bottom of a valley that experiences many months of darkness - the mountains hide the sun - they apparently have had a lot of SAD, etc. The built a large reflector on top of one side of the valley that reflects a large amount of light over most of the village, extending the apparent daylight hours. No photovoltiacs - just reflected light. Improved the village life massively.

Subject: RE: Should we install Solar Power?
From: The Fooles Troupe
Date: 14 Jan 08 - 05:42 AM

I seem to remember that the Aussie guy who worked on that film printing process at the CSIRO was unable to use that process, due to legal constraints, so went off to China to start his own billionaire solar cell industry...

Subject: RE: Should we install Solar Power?
From: Rowan
Date: 14 Jan 08 - 10:47 PM

If you have a system that has some fluid that does not freeze easliy this will be better. I have had solar collectors that freeze

Open Mike,
Without reading back I'm not sure which of the postings you're responding to, and you might already be familiar with what I'm about to say, but here goes.

In Oz, there are generally two types of solar powered hot water systems that use thermosiphoning to heat the water. An "open system" supplies water to both the storage tank and the thermosiphoning part of the system; the water is usually potable and thus can have no antifreeze added to it. Frosty nights can routinely cause the water in the heat collecting tubes to freeze and burst, leaking precious water out of the system; they gave solar hot water systems a bad name, as the only way to prevent the freezing was to drain the collectors every night. Pain in the rear end!

A "closed system" has the water in the heat collecting tubes isolated from the (potable) water in the storage tank. Heated water in the collecting tubes goes through a heat exchanger in the storage tank, heating up the water in the tank, before returning to the bottom of the collecting tubes. The isolation means the water in the collection tubes and heat exchanger can contain glycol (quite toxic when ingested) or any other antifreeze. Depending on the lowest minimum overnight temperature expected and the limit (ie, freezing point) of the antifreeze, you may never have to drain the collecting tubes.

And yes, Grundfos do make water pumps to cope with high temperatures.

Cheers, Rowan

Subject: RE: Should we install Solar Power?
From: Mr Happy
Date: 15 Jan 08 - 05:07 AM

..........but who'd want one of these? http://www.metaefficient.com/accessories/the-worlds-first-biodegradable-umbrella.html#more-1021

biodegradable-umbrella?

So after 2 years it disintegrates without warning & you get soaked!

Aaaarrrrgggghhhh!!

Subject: RE: Should we install Solar Power?
From: The Fooles Troupe
Date: 15 Jan 08 - 06:46 AM

Looks just like the Asian Bamboo & waxed paper ones - they last for ages if you dry them out carefully - they are probably cheaper than the 'biodegradable plastic crap' ones - and more 'eco-friendly' too - don't need to use oil for a raw resource...