Here is an idea, get a regular (say) Holden V6 engine, convert it to natural gas, and connect it to a 100KW electricity generator. You should be able to find something from an army disposal sale. Total cost, say $2000 for the engine and $3000 for the generator for a total of $5000 plus a bit of elbow grease. Make sure the genny can supply a peak of 100KW, but typically put out say
20KW of constant reliable power.Then get all your neighbours (preferably the whole street) to sign up to your "electricity company" and make money!
Let's do the math to see if it is viable:
According to Origin Energy, gas is 1.1021 cents per Megajoule (in Melbourne metropolitan area, Australia)
So One Watt (W) is 1 Joule per second, 1W=1J/s. So a kW=1000W=1000J/s. There are 60*60 seconds in an hour, so a Kilowatt hour is
3600*1000 J=3.6*10^6 J. One mega-joule is 1 million Joules, 1MJ=10^6 J, so 1 kWh=3.6 MJ.So with gas, 3.6MJ, or 1KWh will cost 3.3 cents.
But 1KWh of electricity from that greedy electricity company costs around $0.18 to $0.20 so what is your break even point?
Now lets say you sell electricity to your neighbours for 18.3 cents per KWh, so you are competitive.... your running profit per KWh is 18.3 - 3.3 = 15 cents.
How long will it take to get that $5000 investment back?
Well you will need to sell 5000/0.15 = 33333KWh to break even. Now how much does the average house use????? That is a big question. My use is around
10KWh per day but the figure seems to vary widely from house to house.Now I will use an average of 10KWh per day per house. Say you have 10 houses connected to your little scheme, just to keep the numbers round. The 10 houses shouldn't overload the 20KW generator, with 100KW peak capacity, so I think that is a realistic number anyway.
So at 100KWh generated per day, it will take 333.3 days, or just under a year, to get your money back.
Will the engine run for a year, non stop? I would say yes. Plenty of taxis clock up millions of km.... and apparently running an engine on natural gas is good for it.
From Wikipedia: Due to the absence of any lead or benzene content in CNG, the lead fouling of spark plugs is eliminated. CNG-powered vehicles have lower maintenance costs when compared with other fuel-powered vehicles. CNG fuel systems are sealed, which prevents any spill or evaporation losses. Another practical advantage observed is the increased life of lubricating oils, as CNG does not contaminate and dilute the crankcase oil. CNG mixes easily and evenly in air being a gaseous fuel. CNG is less likely to auto-ignite on hot surfaces, since it has a high auto-ignition temperature (540 °C) and a narrow range (5%-15%) of flammability.[6]
CNG emits significantly less pollutants such as carbon dioxide (CO2), hydrocarbons (UHC), carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx) and particulate matter (PM), compared to petrol. For example, an engine running on petrol for 100 km emits 22,000 grams of CO2, while covering the same distance on CNG emits only 16,275 grams of CO2. [CNG is essentially methane, i.e. CH4 with a calorific value of 900 Kj/mol. This burns with Oxygen to produce 1 mol of CO2 and 2 mol of H2O. By comparison, petrol can be regarded as essentially Benzene or similar, C6H6 with a calorific value of about 3,300 Kj/mol and this burns to produce 6 mol of CO2 and 3 mol of H2O. From this it can be seen that per mol of CO2 produced, CNG releases over 1.6 times as much energy as that released from petrol (or for the same amount of energy, CNG produces nearly 40% less CO2).] The corresponding figures are 78 and 25.8 grams respectively, for nitrogen oxides. Carbon monoxide emissions are reduced even further. Due to lower carbon dioxide and nitrogen oxides emissions, switching to CNG can help mitigate greenhouse gas emissions.[6] The ability of CNG to reduce greenhouse gas emissions over the entire fuel lifecycle will depend on the source of the natural gas and the fuel it is replacing. The lifecycle greenhouse gas emissions for CNG compressed from California's pipeline natural gas is given a value of 67.70 grams of CO2-equivalent per megajoule (gCO2e/MJ) by the California Air Resources Board (ARB), approximately 28% lower than the average gasoline fuel in that market (95.86 gCO2e/MJ). CNG produced from landfill biogas was found by ARB to have the lowest greenhouse gas emissions of any fuel analyzed, with a value of 11.26 gCO2e/MJ (over 88% lower than conventional gasoline) in the low-carbon fuel standard that went into effect on January 12, 2010.[7]
BUT, Back to the story,.... how long will that Holden engine really last? Hard to say, without actually giving it a go, but let's do some more educated guesses.
A regular Holden Commodore is pretty shagged with 300 000 km on the odometer. So lets use that as a base. How many hours of operation would that be?
Now if we use the engine as a generator, it's fair to say that we are treating the engine nicely. There are no cold starts, the acceleration is smooth, there is no stop-start traffic like you have on a real road, so you could maybe assume that if it was compared to a car driven carefully and nicely on the road, and you treated it right, it could make the 1 million km mark without having to be re-built. OK OK, I know what you're thinking, overly optimistic, let's make it more like 500 000 km. How many ***hours*** of operation is that. Well assuming 60 km per hour average, that's 8333 hours of operation.
Now we broke even after 333 days of operation, which is 7992 hours, so
8333-7992 = 341 glorious hours of selling electricity at 100% profit.341/24 = 14.2 days, and with 100KWh sold per day, thats 14.2x100x0.183= $259.86 dollars of cold hard profit, before the engine gets changed over.
OK probably not worth the trouble. Never mind, carry on, nothing to see here.