> Not to compare the Lister with a 2 stroke petrol engine - but have 
> you
> seen any comments on the $99 2 stroke genset that supercheap autos 
> are
> advertising?
> Only 350VA IIRC but even so $NZ99 seems very cheap.


I purchased a 700 watt nominal petro genset recently for $NZ99 from 
Benchmark. They said it was their standard price (!!!).

The problems with this as a competitor with mains power are:

- Hours before maintenance would be low.
- Petrol costs about 50% more than diesel for same energy content.

Say unit would run for 1000 hours with no maintenance.
It may well not last that long ! :-(
$99/$1000 = $0.10/hour.
Assume 750 watt electrical and 80% efficient overall and 10 kWh/litre 
for petrol and $1.40/l and 15% of output is electrical.

All these assumptions are wrong !!!! :-)
But:

Output = 0.75/.15 = 5 kW (750 W elec, 4250 W heat).
Energy in is 5 kW/0.8 = 5.25 kW.
Fuel/hr = 5.25/10 = 0.525 l
Fuel cost/hr = .525 x $1.40 =~ $0.75

If we throw unit away at 1000 hrs cost per hour is $0.85/hr = 
$0.17/unit

That's about the cost of electricity per unit now !!!!!!!!!!!!!!!
Use a Lister where we don't throw it away (but it costs $500 - $1000 
to find the parts to start with) and the incremental cost is below 
mains electricity cost.

I'm SURE the above is quite wrong in places (quite apart from possible 
errors) but it's given me enough food for thought to see what my 
genset will actually accomplish. Being able to use the heat is a major 
issue. Good hot water storage would help. .

Being able to store electric power would be useful but battery costs 
get nasty.

Shame that electricity component is typically so small.




        RM
 

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist