Navitron Renewable Energy and Sustainability Forum

SOLAR THERMAL => Solar (and other) Data Logs => Topic started by: Dan on October 06, 2009, 02:55:45 AM



Title: A year later was it worth it
Post by: Dan on October 06, 2009, 02:55:45 AM
It was around this time last year I did a DIY install. e.g an east /west installation 20x47 mm tubes each side with a 172L tank. During feb this year i put extra installation in the roof and in mid march turned the central heating water heating off. Its only in the last week have i turned the heating on again.

So what are the results ?

well according to my gas bills i used 1547 units of gas between sept 2007 to sept 2008. I then used 1024 between sept 2008 to sept 2009 an approx difference of 500 units but because of the way gas is billed its about a 200 quid saving a year. In total it cost about 1900 approx to buy so I don't feel hard done by.

It will be interesting to see what difference the roof insulation will make to the gas bill.  

Has anyone else got any results want they want to share ?


 


Title: Re: A year later was it worth it
Post by: PhatBob on October 06, 2009, 09:08:13 AM
So you're receiving a little over a 10% tax free return on your 1900GBP investment?
Your roof is outperforming most of the financial institutions - and you've index linked your investment against oil prices.

That's got to be a good thing.


Title: Re: A year later was it worth it
Post by: rob26440 on October 06, 2009, 09:56:39 AM
Dan,

Here are mine and some others.  http://www.navitron.org.uk/forum/index.php/topic,8634.0.html


Title: Re: A year later was it worth it
Post by: dhaslam on October 06, 2009, 10:42:18 AM
The problem is that when you are economical the savings don't seem like very much but I was speaking to someone recently that had an 800 euro electricity bill  in a newish house for two months in the summer.  This is about 70kwh per day.  A lot of it, possibly one third to half,  would be the immersion  but also a lot would be lights on during the day and TV on all day.    In that sort of situation there would be  much bigger adjustment by fitting solar panels. 


Title: Re: A year later was it worth it
Post by: rob26440 on October 06, 2009, 01:25:26 PM
Quote
[In that sort of situation there would be  much bigger adjustment by fitting solar panels./quote]

Easy way to save more... Point them in the direction of the "off" switches!


Title: Re: A year later was it worth it
Post by: KenB on October 06, 2009, 08:45:49 PM
70kWh per day!

I struggle to use 5kWh. What on earth were they doing with all that energy?


Ken


Title: Re: A year later was it worth it
Post by: dhaslam on October 06, 2009, 10:27:33 PM
It is quite impressive to be able to use so much.    One of the problems is the lighting in the stairwell.  I have heard of houses using 2kw for spotlights and this house has spotlights on the stairs, I am not sure how many,  which the kids keep leaving on.    There is a series on TV in Ireland at present about three families money wasting.    Energy is only one  factor but quite  revealing.   One family was using 4000 euro worth of oil per annum because the house thermostats weren't cutting out the boiler. The boiler was apparently able to lose that amount of heat in the feed to the under floor heating distribution point but this wasn't even mentioned.   


Title: Re: A year later was it worth it
Post by: RichardKB on October 06, 2009, 11:19:32 PM
I use 3 units per night on economy 7 for water heating so approx 77 per year if I could save half of that by installing your 1900 system then at current prices it would take 50 years to break even and that assume no running repairs etc.

Rich


Title: Re: A year later was it worth it
Post by: dhaslam on October 07, 2009, 10:10:39 AM
If you only use 50 litres of hot water a day you would probably get about 75% of your annual needs so it is would be about 3% return, indexed to energy cost, still better than most banks will do. 


Title: Re: A year later was it worth it
Post by: Paul Bradford on July 07, 2017, 09:18:39 PM
In the Summer of 2008 I installed my system. 20 tubes, South facing and a 200 litre tank. The total cost of the system, including transport and road tolls to and from where we live in France, Channel Tunnel, hotels bills and all the copper pipe and fittings which I bought in the UK as they were cheaper, plus paying a central heating engineer friend to tidy up the copper pipework to the boiler as I can't braze, amounted to under 1500. Each year since, we have saved 500 litres of fuel oil for the boiler. The system paid for itself in less than four years. Four years ago I changed the tank to a more modern, thermally efficient 500 litre tank. That cost around 1200 fitted, but I figure that it has been paid for by the savings. Straight away we noticed a difference. Our water was hotter and we had more of it. 2017, still saving and still enjoying the free hot water! exhappy: