Generators

[Joshd]

So you get 41.3p for the electricty you make from wind turbines etc. Or i am misunderstanding you.

[Justme]

So you get 41.3p for the electricty you make from wind turbines etc. Or i am misunderstanding you.

 

Sorry you get 41.3p per unit for retro fitted PV under 4kwp for 25 years. You get less for an install that goes in as the house is built. Wind gets less & for less time (20 years).

 

 

[Robin2]

That cost per kWh is actual recorded costs & has stayed stable with fuel costs for the last 2 1/2 years & include regular (in excess of makers recommendations) servicing (but not bat replacements). I guess that due to running a genny instead of a boat engine to provide the power. It also has a self limiter so that its using exactly the fuel needed to provide the power output, using a boat engine & trying to match the revs to alt load can be hit & miss. Prob a good idea to have an amp meter so you can change the revs to match the load. Also making sure that the genny is running under load as much as possible but not maxed out. IE do the washing when the bats need a good charge but wait till the bats have taken a good bit so you dont max out the genny.

 

I have been thinking more about this as I would love to get my generation costs down to this level. I have a few questions (and please don't think I am trying to disprove your figures - I am just trying to understand in a way I can relate to my own situation).

 

• 
   
  
• I assume the 55p is not taking account of electricity from your solar panels.
  
• Is 55p the cost of the output from the generator or the cost of the electricity consumed (less kwhrs will be consumed due to battery losses).
  
• Assume diesel costs 70p/litre. Then if the 55p is based on your genny producing an average 1kw (83amps a 12v) it will consume 0.78l/hr, if producing 2kw on average it would consume 1.57l/hr (for half the time) and if the average was 0.5kw the fuel usage would be 0.39l/hr. Is any or all of these correct for your system? (with appropriate adjustments if your fuel cost is different). My problem is finding a generator that generates a small amount of power with a proportionately small amount of fuel.
  
• Roughly how many kwhrs do you use per year? I wonder if you use more than me and if, paradoxically, that helps to keep the kwhr price down. Ultimately, of course, the total annual fuel bill is more important than the kwhr price.
   
  

Thanks.

[nb Innisfree]

I have been thinking more about this as I would love to get my generation costs down to this level. I have a few questions (and please don't think I am trying to disprove your figures - I am just trying to understand in a way I can relate to my own situation).

 

• 
   
  
• I assume the 55p is not taking account of electricity from your solar panels.
  
• Is 55p the cost of the output from the generator or the cost of the electricity consumed (less kwhrs will be consumed due to battery losses).
  
• Assume diesel costs 70p/litre. Then if the 55p is based on your genny producing an average 1kw (83amps a 12v) it will consume 0.78l/hr, if producing 2kw on average it would consume 1.57l/hr (for half the time) and if the average was 0.5kw the fuel usage would be 0.39l/hr. Is any or all of these correct for your system? (with appropriate adjustments if your fuel cost is different). My problem is finding a generator that generates a small amount of power with a proportionately small amount of fuel.
  
• Roughly how many kwhrs do you use per year? I wonder if you use more than me and if, paradoxically, that helps to keep the kwhr price down. Ultimately, of course, the total annual fuel bill is more important than the kwhr price.
   
  

Thanks.

 

Our Kipor 2kva digital genny uses petrol at 0.9 lph at rated output (1.6kva) and half a tankful gives 8 hr absorption at tickover which relates to 0.23 lph. Shame an equal diesel genny with that level of lightness and noise isn't available.

Edited December 31, 2010 by nb Innisfree

[Justme]

 

 

1, [*]I assume the 55p is not taking account of electricity from your solar panels.

2, [*]Is 55p the cost of the output from the generator or the cost of the electricity consumed (less kwhrs will be consumed due to battery losses).

3, [*]Assume diesel costs 70p/litre. Then if the 55p is based on your genny producing an average 1kw (83amps a 12v) it will consume 0.78l/hr, if producing 2kw on average it would consume 1.57l/hr (for half the time) and if the average was 0.5kw the fuel usage would be 0.39l/hr. Is any or all of these correct for your system? (with appropriate adjustments if your fuel cost is different).

 

4, My problem is finding a generator that generates a small amount of power with a proportionately small amount of fuel.

5, [*]Roughly how many kwhrs do you use per year? I wonder if you use more than me and if, paradoxically, that helps to keep the kwhr price down. Ultimately, of course, the total annual fuel bill is more important than the kwhr price.

 

Thanks.

 

1, Correct, If i count the solar then my average cost per unit is 29p

2, 55p is the cost per unit consumed via the consumer unit.

3, I paid 53p inc vat last time per L.

4, very low loads are cheaper with a very small petrol genny.

5, This year minus all of Dec as I have not read the meter yet (thats tomorrows job)we have used 1169 kwh (I expect we will have used about 130kWh in Dec) & the genny has made 1198 kWh (the solar made 650kWh pre bat charging) So I have charged with (or used whilst charging) 1848kWh.

 

The genny has run for 690 hours so an average of 1.73kW's per hour. But I also have an unmetered supply from the genny that I run things like the welder & power tools off (a lot this year). So my true cost would be even lower had I metered that supply (which I have the meter for its just not fitted yet.

Its quoted consumption is 1.4L per hour at an average load. I must run at slightly lower that "average" as I get better than that at about 1L per hour.

(I also use a higher spec oil & change it at half the recommended hours & swap air filter sooner than spec too). I do also think that as I mainly use it in winter the cold air helps.

 

From the above you can also see that you get about 30% losses due to bat charging & inverting. Thats slightly higher than I expected but not to far out.

 

 

The L per hour ties up with the hours run & the volume of fuel I use. If all power was used direct & both outlets were metered then I guestimate that the true cost per kWh would be nearer 40p inc servicing costs but not capital or replacements. Thats ties in with the cost that Mat B is paying for communal power used when made leaving some "profit" for replacements & paid for services.

[Gibbo]

With some of the FITs quoted in that table I smell a scam buying electricity off a neighbour and selling it back to the local supplier.

 

What systems are in place to stop this?

[Justme]

Not much point selling it back to the supplier as you only get paid 3p per kWh for exports & any you buy will be more like 12p (some meter this & some use 50% of total generated).

 

You have an approved total generated meter fitted between the PV inverter & the CU. This reads the total made & you get paid 41.3p per unit from this reading even if you have used it yourself (in fact its best to use it all if you can cos you only get 3p per unit for exported & you will be paying more for imports).

 

Your own meter is not allowed to turn backwards.

 

Some have export meters.

 

It has to be installed by an approved supplier.

 

Your elec company should be inspecting it at meter read times

(mine asks for a picture to prove the reads in between reads that they do physically)

 

They also have a good idea how much power say a 1kWp PV system will produce per year & if you go over that they will pull you out for an inspection.

Edited December 31, 2010 by Justme

[Robin2]

 

 

A very comprehensive answer - thank you.

[nb Innisfree]

With some of the FITs quoted in that table I smell a scam buying electricity off a neighbour and selling it back to the local supplier.

 

What systems are in place to stop this?

 

Or charge a load of batts up and take them to someone far away and sell the power, no? Ok.

[Justme]

There has been fiddling in another country, people using gennies to power a PV system's meter. They got found out as they were doing so at night

[Robin2]

There has been fiddling in another country, people using gennies to power a PV system's meter. They got found out as they were doing so at night

 

It's called moonshine