Renewables: "talking 'bout my generation"

Martyn1981

John_Pierpoint wrote: »

Perhaps it is the CO2 emissions that have jammed the jet stream and turned 2012 into the year with no summer?

Now wouldn't that be ironic, climate change reducing the effective ability of renewables to effectively reduce climate change!

Got a 9 yesterday, against daily target of 13. Week 1 closed on 48, against target of 91. Worst week since week 2 of March.

Looks like a better week coming up, but still pretty bad for July. Large parts of Wales have already exceeded July's average rainfall for the month. Maybe I should ditch the PV and install downpipe micro-hydro systems instead? :rotfl:

Mart.

jackieblack

6kWh generated here yesterday
75kWh generated so far in July,which averages a little over the 8kWh per day I need to meet target

EricMears

Martyn1981 wrote: »

. Maybe I should ditch the PV and install downpipe micro-hydro systems instead? :rotfl:

Mart.

I'm sure you were joking but just in case anyone takes the remark seriously I should point out that you need an awful lot of water going past a turbine to generate anything worthwhile.

A 100 sq m roof is quite large, 1000mms of rainfall is a year's average for most of us so 100 cu m would be a typical years collection. My 1kW pump shifts 100 litres in five mins so about a cu m per hour. i.e. I could pump a whole year's worth of rain with 100kWh of power. A generator wouldn't produce as much as 100kWh from that amount of water but let's pretend it would: that's only about 0.3 kWh/day on average.

Martyn1981

EricMears wrote: »

I'm sure you were joking but just in case anyone takes the remark seriously I should point out that you need an awful lot of water going past a turbine to generate anything worthwhile.

that's only about 0.3 kWh/day on average.

Cheers Eric, you could have told me sooner. I've already printed out all the application forms for Dragon's Den now! :mad:

Best quote I've heard lately about this summer

'mildest winter I can ever recall'

Mart.

Oscargrouch

Martyn1981 wrote: »

Cheers Eric, you could have told me sooner. I've already printed out all the application forms for Dragon's Den now! :mad:

Best quote I've heard lately about this summer

'mildest winter I can ever recall'

Mart.

Looking at Erics figures; have you thought about recycling the rain water after it has passed through the turbine? On the basis that when it is not raining you could use a pump, (as Eric does) to put the water on the roof again and, use it as often as you will. Once it has passed through the turbine you could create a series of waterfalls (these would be nice) through your garden to a holding tank just below ground. This would ensure that you have adequate water during any dry spells we may have during the winter. You would obviously use your solar power to drive the pump during no-rainfall days (not often); when it is raining you would not need to use it. You would, of course, need to ensure that once water has passed through the turbine it goes into your holding tank, with adequate overflow facilities. I appreciate that this would mean having PV as well, but back-ups are always use-full, and your tanks would be similar!:rotfl:

9.1 kWh today, had to give the Inverter a wake up call this morning, as at 08:15 it had not started. Needed to disconnect from the mains and re boot it; that did the trick. :T Started putting in 0.012kW. :rotfl:

EricMears

Oscargrouch wrote: »

Looking at Erics figures; have you thought about recycling the rain water after it has passed through the turbine? On the basis that when it is not raining you could use a pump, (as Eric does) to put the water on the roof again and, use it as often as you will. Once it has passed through the turbine you could create a series of waterfalls (these would be nice) through your garden to a holding tank just below ground. This would ensure that you have adequate water during any dry spells we may have during the winter. You would obviously use your solar power to drive the pump during no-rainfall days (not often); when it is raining you would not need to use it. You would, of course, need to ensure that once water has passed through the turbine it goes into your holding tank, with adequate overflow facilities. I appreciate that this would mean having PV as well, but back-ups are always use-full, and your tanks would be similar!:rotfl:
:rotfl:

What you're describing here is a 'pumped storage system' - but it would be exceedingly difficult to get a useful amount of water stored at roof level. I have two very large tanks in the attic holding about half a tonne. Weight distribution was carefully arranged so that a structural wall takes all the load. Possible somene else might be able to store more than that - but unlikely it would be hugely more. From the calculations above, a tonne of water on the roof might be worth up to 1kWh (but probably rather less)

EricMears

7.07 kWh today

No spells of direct sunlight although we had a peak of around 2.5kW at 11am when the thin clouds were giving a decided 'glare'.

Oscargrouch

EricMears wrote: »

What you're describing here is a 'pumped storage system' - but it would be exceedingly difficult to get a useful amount of water stored at roof level. From the calculations above, a tonne of water on the roof might be worth up to 1kWh (but probably rather less)

I am not describing storage at roof level, merely using the roof to pass water through the turbine and then re-use (the water) as and when required.:rotfl::rotfl:

shafeeq

hi

3.59kw.. my system seems to be the worse one.

Shafeeq

EricMears

Oscargrouch wrote: »

I am not describing storage at roof level, merely using the roof to pass water through the turbine and then re-use (the water) as and when required.:rotfl::rotfl:

but !!

Oscargrouch wrote:

when it is not raining you could use a pump, (as Eric does) to put the water on the roof again

Without storage tanks, the water would hit the turbines almost immediately and generate about half the energy just used to pump it up to roof.

On it's first run through such a system, a typical annual rainfall on a typical roof might perhaps generate 100kWh per year (saving £10 from your annual bill). Even with a 1 tonne tank filled by solar PV & emptied at night you'd only generate a further 365 kWh (saving £40 from your annual bill). If the 'investment' was to make any financial sense, saving £50 on an annual electricity bill could justify a maximumum capital cost of around £500 and I've got grave doubts that would buy the required kit.