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Solar panels and solar water heating


Northwarks

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So ignoring the instal costs for now ... 

 

I have a large South facing roof in the Midlands, I work from home so use lights and laptop/desktops all day, have a tea habit :d

 

Does anyone have any experience of actually owning a roof of solar panels? I'm no eco-warrior but wondering if there is any savings to be made on the day-2-day running of the house by having a roof of panels and a solar heating panel for water. I know the feed in tariffs were changed 'recently' so theres less chance of earning any £££ but that doesn't really interest me - I just want to know if theres savings to be made in the real world, would they generate enough energy on an average  day to reduce my leccy bill?

 

Kev F

 

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Yes, Kev. I have 17 panels on a South facing roof in Essex. A little shading in the evening, but has produced 3.4- 3.5 MWh each year for the last 3 years. So 10 KWh per day on average, but in reality it's more like 2-3 kWh per day in Nov-Feb, then 10 on a cloudy day through Spring- Autumn and 20 on a sunny day. You can use an immersion heater instead of a solar water panel, too...

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mine generate up to 20kwh per day in the summer .halved my electricity bill .and use immersun  controller to heat up water from solar panels all year around . [only uses excess power to heat immersion heater] if you get a bigger water tank and long immersion heater then should be able to have enough water for whole family no problem. I turn of my gas boiler in the summer not needed.

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Hi Kev,

I have had solar hot water and photovoltaics on a boat for the last six years. Lots of experience with them. I have sent you a looonngg PM.

 

Jen

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I had panels fitted in Nov 2011, and they have performed well, normally about 110-130% of expected. (the roof does point directly south and has no shade) a friend has a similar roof but at a lower angle and doesn't get as good results. It seems the panels perform a lot better when at the optimum angle on both axis. (newer panels may be less fickle)

 

As the others have said I run the hot water from an immersion on a timer, which works well in the summer but the output of the panels falls a lot in the winter. If you ignore the feed in tariff then we have made a saving (mainly due to being able to turn the oil boiler off in the summer as the panels do the hot water) but the saving wouldn't be enough to justify the cost. Once you add in the feed in tariff then it is a different kettle of fish and the numbers certainly add up.

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It's no good asking people who have them, when you've spent £15'000 on something you don't turn around and say "actually everyone was right, they're not saving me anything at all". They have a placebo effect, you kinda just assume they're saving money because that's what the salesman told you. But I think even at current rates, 15000 in the bank is going to collect more interest than it'd save attached to your roof.

 

They're also becoming a bit like conservatories, once one person gets one, the whole street has to keep up.

 

Even in mid summer, with full light on them, they're not enough to run a high power appliance. What you are in fact doing is paying to have your house used as a solar generation point. You don't have batteries, so your not storing what you generate.

 

If someone came to you and said "we want to stick a wind turbine in your garden", you'd say "hey, f**k off, not unless your paying me.......", equally if they wanted to turn the neighbouring field into a solar farm, everyone would be up in arms. But with some clever marketing they get almost exactly that, only you pay them for it.

 

Solar water heating on the other hand (much more efficient that converting light into electrical power), that could be a massive money saver and really quite easy to DIY the panels with the raw materials. I've actually done some initial experiments and managed to heat half a litre of water to near 170c in just short of 1 hour. Whilst my solar power experiments have been nothing but a disappointment.

 

I'm all for being "green", but lets do that by making stuff last longer, instead of ramping up production of consumer goods and making them last less than half as long as they should.

 

Just my 2p worth :p

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Lyonspride, I'm not sure that your first comment is correct, I actually said that without the feed in tariff its not worth it.

 

With the feed in tariff the numbers are: cost £11,500  energy savings in the first 3 years estimate at £450 FIT payments £6,120. So in the first 3 years I have made 57% of my outlay back and the FITs payments are index linked and payable for the next 22 years.

 

I don't know what the current tariff is for new installs, but like I said with out the feed in tariff, the numbers don't add up.

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The feed in tariff, isn't that coming from the govt as an incentive to go solar?

What if they stop that? They slashed it by half just a few years ago.

 

http://www.moneysavingexpert.com/utilities/free-solar-panels

 

Seems like a gamble to me, and only worth it IF they would add their own value to the sale price of your house.

 

The issue for me is that govt ministers and their public school friends (now with shares in the biggest corporations in the world), have vested interests in the renewable energy sector, they're not doing this for our benefit.

Hence why you can't install your own panels and get the feed in tariff.

 

Like I said, if they were trying to save the planet, they be discouraging the raping of it's resources, but instead we're encouraged more than ever to go out and buy more new stuff, all in the name of being "green".

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Lyonspride, the OP asked for experienced feedback. Please don't skew this thread with ill-informed ranting. No offence.

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Some other things to consider-

You have to have an energy performance certificate these days before FIT is paid out, believe you have to be an E or better to qualify.

The max power generation in a domestic home is limited to 3.9kw.

FIT payment per kwh has somewhat reduced in recent times from the heady heights of 43ish Pence per kw down to 11pence I believe.

You also receive about 3.5 Pence per kw from your electricity supplier, this is estimating that you export 50% of you total generated kw's and you are paid for 50% of       electricity produced by yourself.   As mentioned above you can cheat it a bit and stop the exported 50% actually going out. 

Install costs have come down because of the reduced take up, you can shop around and buy the panels yourself then find an approved installer, as long as he can produce a FIT Certificate.  I did it this way and forked out £7000 all in for a 3.9kw system, electric only. Still going to be payback term estimated at 7.5 years.

 

What you need to do is a lot of maths and meter readings to estimate the energy you are going to produce and what you are going use during daylight hours. Our house is empty during the day so have not noticed a significant drop in kw's consumed overall, hopefully you will, all depends on your lifestyle.

I only had mine installed as I had some spare cash floating around but missed the Bandwagon 43 per kw.   I'm on 21 pence per kw.

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I prefer "over-informed" :)

 

Everyone who has them seems to praise them, but then everyone who spends crazy money on a car does the same, regardless of the poor reviews. So I just apply the same logic.

 

I'd like to get an opinion from those who had them for free and where the provider keeps the FIT payments, but I suspect those opinions might be skewed unfairly the opposite way, as a lot of people had mortgage problems when their banks realised they effectively no longer owned the roof of the property. :(

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Hmm, if they were freely installed with no FIT, would I have them? Still yes, because I can dump 7kWh per day to my hot water instead of burning £1 of oil. But honestly at that point I'd choose solar hot water instead, so can't really make a fair non-FIT assessment.

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Solar photovoltaics are a bit rubbish in the UK. Too far north. Too little direct sunlight. On an overcast day the power out from mine drop by nearly an order of magnitude. Solar hot water on the other hand is a worthwhile thing. It is just that photovoltaics had the huge subsidies and incentives a few years back and solar hot water did not, so a lot more people have them on their houses. I have had both for six years on a boat, so am off grid for some of the time. For me photovoltaic panels are useful in summer. If I went to living back on the land again and there were no subsidies I would invest in solar hot water before photovoltaics.

 

Jen

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I'm still thinking about having solar heated water but with no hot water storage whatsoever I'd be starting from scratch. one upside is that I can do all the plumbing work myself, just have to buy all the kit.

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I'm still thinking about having solar heated water but with no hot water storage whatsoever I'd be starting from scratch. one upside is that I can do all the plumbing work myself, just have to buy all the kit.

 

Do you mean full DIY? or buying the units ready made?

 

They're little more than a box full of black painted copper (or alloy) tube, with polycarbonate on one side and all the air sucked out in the middle (kinda like a double glazed window).

The pipes are filled with anti-freeze, it leads off to a heating coil inside your hot water tank and a pump circulates the water through.

 

But either way they're really quite efficient, even if you just use them to supplement your existing boiler.

 

Light to heat is far more efficient than light to electricity.

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