Rooftop Solar Panels

[wim121]

Hmm, very promising. Any customer reviews?

One thing I did spot though is that it's geared for 14 m/s winds. Average for UK throughout the year is 6 m/s (IIRC), and at 6 m/s that unit outputs a puny 50 watts

Not any reviews on those cheap kits, not that I can see. I was looking last year at the £300-£500 bracket. I cant see the exact same kits available anymore though

Looking now (typing in wind turbine kit), at the sub £500 you can find 800w turbines, even 1KW+ ones if you're prepared to bid/best offer. I used an anemometer and I get a pretty regular 10m/s in late summer (what passes for it up here) above my rooftop, where I would probably mount a turbine, didnt test it in autumn/winter but I presume it would be a bit higher.

With the right gearbox, conditions, etc, I estimated I could get about 250w output on average per hour, 40p every four hours, if I spent right up to £500 on a good kit. So there are 8760 hours a year, divided by four would equal 2190 then multiply by 0.40 equals £876 back per year. However in that figure as well, I would have to pay on top of the turbine, the cost to hook it up to the grid, meters, anchoring to the beam/brickwork and redoing an area of rooftop, any replacement blades or a more efficient spare fan, etc, all that would cost the project up to nearly £1k. So one year to one and a half, could recouperate all incurred costs theoretically .....

Before I go any further though, I really need to clarify my wind speed with more accurate year round readings. Also Im not sure if I can be bothered at the moment as Ive just had a lot of building work done.

[TimberWolf]

Not any reviews on those cheap kits, not that I can see. I was looking last year at the £300-£500 bracket. I cant see the exact same kits available anymore though

Looking now (typing in wind turbine kit), at the sub £500 you can find 800w turbines, even 1KW+ ones if you're prepared to bid/best offer. I used an anemometer and I get a pretty regular 10m/s in late summer (what passes for it up here) above my rooftop, where I would probably mount a turbine, didnt test it in autumn/winter but I presume it would be a bit higher.

With the right gearbox, conditions, etc, I estimated I could get about 250w output on average per hour, 40p every four hours, if I spent right up to £500 on a good kit. So there are 8760 hours a year, divided by four would equal 2190 then multiply by 0.40 equals £876 back per year. However in that figure as well, I would have to pay on top of the turbine, the cost to hook it up to the grid, meters, anchoring to the beam/brickwork and redoing an area of rooftop, any replacement blades or a more efficient spare fan, etc, all that would cost the project up to nearly £1k. So one year to one and a half, could recouperate all incurred costs theoretically .....

Before I go any further though, I really need to clarify my wind speed with more accurate year round readings. Also Im not sure if I can be bothered at the moment as Ive just had a lot of building work done.

Figures seem to add up. I've a very vague recollection of 4 years return on wind mentioned, in theory. But in practise probably a lot longer and might be worth speaking to someone who has actually done it. I think Cameron's wind turbine was a famous spectacular failure?

As you say, solar thermal could be done dead cheap too. I know from the days when I had a south facing double glazed balcony, how hot that place got in winter when the sun was out - in the mid 20s. A black insulated box full of water could do much better.

[wim121]

Figures seem to add up. I've a very vague recollection of 4 years return on wind mentioned, in theory. But in practise probably a lot longer and might be worth speaking to someone who has actually done it. I think Cameron's wind turbine was a famous spectacular failure?

As you say, solar thermal could be done dead cheap too. I know from the days when I had a south facing double glazed balcony, how hot that place got in winter when the sun was out - in the mid 20s. A black insulated box full of water could do much better.

I think the main difference, be it wind turbines or solar thermal, is the cost between doing it yourself and paying a company. I would imagine the payback length would be horrible with a company charging thousands, compared to a quick payback in a year or so spending hundreds on the DIY approach.

On wind, just browsing kits on ebay, found this kit as an example, which appears to be a bit better than the horrid cheap chinese kits. They also give stats as well:

FSW, LLC. 2kw Wind Generator System Output

Avg. Wind Speed Watts/Hour Produced Kwh’s/Month Produced Avg. Annual Energy Prod.
5m/s 250 180 2,160
6m/s 550 396 4,752
7m/s 875 630 7,560
8m/s 1,375 990 11,880
9m/s 2,000 1,440 17,280

So in my previous estimate would apply to this turbine at 5m/s constant wind speed, 250w p/h, which is an easy figure to obtain in the UK.

http://www.ebay.co.uk/itm/1805460034...84.m1423.l2649






As for solar thermal, found a DIY guide on a quick look on google from someone that did their own thermal system. He calculated on prices he spent approx £400 pa (£33.33 pm) on hot water heating, so he got these quotes:

Quote 1: ( Bournmouth ) Two hour high pressure visit. 1 solar panel, 40 gallon hot water cylinder, pump and box of electronics, £11,500 or £6,400 if ordered within 24 hours.
Quote 2: British Gas claim you can save £85-£350 a year with their system, costing £3600.00. Will take from 10.2 to 42 years to pay for it self ( is nothing goes wrong ).
Quote 3: Solartwin. £3,699 installed or £2,699 DIY.
Quote 3: According to the Energy Saving Trust, the average price for a system is £4800.00.
Quote 4: Whilst visiting an energy display in my area I was quoted up to £10,000 for thermal panels.
Quote 5: British Gas latest. Approximate cost for a system £ 5000.00 inc VAT ( At least 30 year payback).
Quote 6: Tesco £ 4,339 ( At least 25 + payback ) Double Clubcard points.

So he built his own, for £604.50 and shows it step by step.

DIY solar Hot Water System build your own

However, I would have relayed more panels if I were him to be honest, have a more efficient system.

[shaunbhoy]

Have you met Shaun? He doesn't have use for a toothbrush. Glass of solution by the bed yes. Toothbrush. No.

At least I don't have a comb-over!!

[TimberWolf]

I think the main difference, be it wind turbines or solar thermal, is the cost between doing it yourself and paying a company. I would imagine the payback length would be horrible with a company charging thousands, compared to a quick payback in a year or so spending hundreds on the DIY approach.

On wind, just browsing kits on ebay, found this kit as an example, which appears to be a bit better than the horrid cheap chinese kits. They also give stats as well:

So in my previous estimate would apply to this turbine at 5m/s constant wind speed, 250w p/h, which is an easy figure to obtain in the UK.

eBay - The UK's Online Marketplace






As for solar thermal, found a DIY guide on a quick look on google from someone that did their own thermal system. He calculated on prices he spent approx £400 pa (£33.33 pm) on hot water heating, so he got these quotes:



So he built his own, for £604.50 and shows it step by step.

DIY solar Hot Water System build your own

However, I would have relayed more panels if I were him to be honest, have a more efficient system.

Hmm, interesting. The term "green thieves" rings a chord Will read it properly later.

I've also heard of thermal ponds coming on stream (and heat pumps). That is, a pond that's left to heat outside in summer and the water pumped under a building in winter. Just two holes and a small pump in essence. Though no doubt by the time the green thieves have had their way it would have become a mega costly project.

[MarillionFan]

At least I don't have a comb-over!!

Of course you don't. You don't have enough to comb over.

[shaunbhoy]

Hmm, interesting. The term "green thieves" rings a chord Will read it properly later.

I've also heard of thermal ponds coming on stream (and heat pumps). That is, a pond that's left to heat outside in summer and the water pumped under a building in winter. Just two holes and a small pump in essence. Though no doubt by the time the green thieves have had their way it would have become a mega costly project.

Sure I saw a programme in which they mentioned that if you drill down something like 150 feet, then the thermal warmth that will rise up would be sufficient to provide most of your heating. Although I might have dreamt that.
Better than multi-nippled dreams I suppose!!

[shaunbhoy]

Of course you don't. You don't have enough to comb over.

I will allow the panel to decide upon this................

MF




Shaunbhoy

[wim121]

Hmm, interesting. The term "green thieves" rings a chord Will read it properly later.

I've also heard of thermal ponds coming on stream (and heat pumps). That is, a pond that's left to heat outside in summer and the water pumped under a building in winter. Just two holes and a small pump in essence. Though no doubt by the time the green thieves have had their way it would have become a mega costly project.

Yea Ive heard of similar systems, like a ground pump, that is essentially a big underground radiator that supplies warmth 24/7, absorbing heat in the ground ...


What I would like to see, if anyone can find such a table, is one comparing heat output to all forms of green energy.


I hate this whole greeny thing, but after I get rid of this house, it's going to be essential as energy prices rise.

[MarillionFan]

I will allow the panel to decide upon this................

MF




Shaunbhoy

ftfy