Question: How profitable is it to run a genset into the grid?

Now, excluding the cost of purchasing a conventional diesel generator and having it converted to run other either fuel, plus the fuel itself, does anyone know the amount of income such a contraption could generate over a year?

I've worked out that could be:

5,000 kwh @ 0.4pence x 24 hrs x 365 days = £1,752,000, or thereabouts (excluding downtime). Now I know these generators produce power in the 4000v to 11000v range. Question: does this mean that I can add to the above equation (for example): 6000v divided by 240v = 25 x the figure given above (£1,752,000)?

In other words: I know these large diesel generators produce a huge amount of wattage (say 5mwh) or high voltage (upwards of 11000v), but can they produce both?

Regards

Phillip Rhodes

Can not speak of UK. Where I live there are plants that are considered "peakers" that can be started and stopped for such use. Smallest near me is 350 meg on natural gas.

I took care of 2 Cat 3516's for emergency power and peak shaving. Each generator was 1400 kw at 5 kv. As you said discounting the purchase, switchgear and controls, we found after 2 years of using them for peak shaving it was costing us more than it would to pay for the increased demand and kWh used. These machines were diesels and they would not be able to produce as much electricity if we had converted them to natural gas. We already had a high pressure line for the boilers. Each engine used 156 gallons an hour at full load.

Not exactly familiar with 5 megawatt gensets, but I would imagine you would not be purchasing a 5 megger that was an internal combustion engine. A turbine sure, not piston powered. I am pretty sure that you could purchase any voltage and amperage combination that you desired.

Hydrogen is not a viable fuel for some thing that large. IMO

Your local utility WILL have a lot of stringent rules and regs before you would be able to connect to the grid. All of these upfront costs would be on you the producer. The real kicker is what will they pay for the electricity? Here unless your considered a utility they do not pay much for the power, like 2/3 of what they sell it for. If your considered a utility then you need to install monitoring and have yearly inspections for pollution.

Where I live a 5 meg plant running 24/7 would be a money pit and would never make any money.

Now, excluding the cost of purchasing a conventional diesel generator and having it converted to run other either fuel, plus the fuel itself, does anyone know the amount of income such a contraption could generate over a year?

I've worked out that could be:

5,000 kwh @ 0.4pence x 24 hrs x 365 days = £1,752,000, or thereabouts (excluding downtime). Now I know these generators produce power in the 4000v to 11000v range. Question: does this mean that I can add to the above equation (for example): 6000v divided by 240v = 25 x the figure given above (£1,752,000)?

In other words: I know these large diesel generators produce a huge amount of wattage (say 5mwh) or high voltage (upwards of 11000v), but can they produce both?

Regards

Phillip Rhodes

First, just a note: Power is measured in watts or metric multiples. So the abreviation for the power is 5 MW, not mwh (drop the 'h'). Total energy is measured in watt-hours (or metric multiples), *that* is where you use MWh

So, a 5000 kW generator, running for 24 hours/day * 365 days/year =

43,800,000 kWh of energy. I'm not sure of UK currency, so I *assume* that 100 pence => 1 pound?? If so, then 43,800,000 * 0.4 pence = 17,520,000 pence = 175,200 pound. But is 0.4 pence/kWh really the price??

Anyway, a large diesel genset might be that big, but it would undoubtedly 'drink' a lot of fuel. Do you have any fuel consumption specifications for the unit you're interested in? There's a simple reason why utilities only use diesel gensets for peaking units. Running them is expensive.

Finally, sadly no. Changing the voltage output of the machine will not change the power output. Raising the voltage up will require you to drop the current by a proportional amount. Think of it this way, if you raise the voltage by 10x and kept the current the same, the generator output would seem to go up by 10x, but you still have the same size diesel engine driving the whole thing. Can't get something for nothing, the generator would just stall the engine completely to a stop.

daestrom P.S. And as SQLit said, hooking up a unit that size to the grid, you have a lot of compliance issues. Both with the utility, but local government (pollution, noise, zoning, fuel storage, etc...)

In case this has not been covered, it doesn't matter what voltage or current you generate at, 5000kW is 5000kW and 5000kWh is 5000kWh. 6000V/240V=25 is not a factor that applies to the economics in the way you have posed the question. By the way, 5000kW is 'power', or, if you prefer, 'Wattage', whereas 5000kWh is 'energy'.

j

itself,

generate

Let's see. You mean 5000 kW, not 5000 kWh. In a year at full output, you'd make about 43.8 million kwh, again neglecting outages. Here in Manitoba I might be able to sell this energy for as much as 6 cents per kwh giving me a gross revenue of $2.6 million Canadian. Haven't priced diesel fuel today but last time I looked it was around 75 cents/litre (bought in moderately large quantities). Checking the Caterpillar gen set site I discover that a litre of diesel fuel at full-load might make as much as 3.8 kWH. So, I'd have to buy 11.5 million litres of diesel costing about $8.6 million per year, for a net loss of $6 million per year. Plus lube oil consumption, maintenance, someone to watch the plant when I'm asleep, plus the interest on the capital cost ( for 5000 kW in an urban setting I'd expect the costs to be $3,000,000-$5,000,000 including transmission lines).

So, diesel engines burning oil are only used to make electricity where you can't get the grid.

As for hydrogen, forget it...even the local sodium chlorate plant which produces tons of hydrogen as a *free* waste product from electrolysis, can't really justify converting the H2 to electricity and instead burns it for heat.

There's a reason why people don't do these simple obvious things: that reason is, that they make no economic sense.

Bill

Rule of thumb: If you are grid connected, it is always cheaper to buy grid energy than to generate it yourself. That means for every $costunit of energy produced, the grid would cost you some fraction of that $costunit. On top of that, the grid will pay you for energy less than they will charge you for the same amount. So you lose twice.

One can strain at a gnat to find exceptions to the above. For example, we produce > 20 megawatts when all the geerators are running, and we run them on the very hot days when the demand is great. We pay a variable rate to the grid - lower when there is low demand, and higher during peak demand. When we fire everything up and are self-powered, we sell the excess to the grid. The cost of the generators/installation/ maintenance/monitoring/running etc is all part of doing business and is not included in the computation of what we make by selling to the grid. So whatever we sell is profit. This has to do with accounting practices which I don't fully understand (to say the least!).

Ed

Not always. My veggie gen costs me $0.06 / kWh after purchase price and expected maintenance, while grid would be $0.15 / kWh ...

They do if you can use the "waste heat,"

2/3 or more of the fuel's heating value.

Nick

Rule of thumb: net metering. Look it up.

Nick

I prefer foot poundish or is it foot pound per secondage?

Bill

Rule of thumb: net metering only applies to small, very small, services.

Charles Perry P.E.

Hey Ed Want to scare yourself. Start looking into all of the costs associated with the power production. I had a couple of 3516's a paltry 2800kw, and when I complied all of the costs associated it was definitely cheaper to pay the utility for the increased demand and kwh. Only problem was it took 3 years for management to finger it out. My numbers were ignored. Another persons numbers were discounted, ok she was a red headed fox, but that did not mean that she was stupid nor did not know how to add. The exhaust issues finally tipped the balance. The engines now run only for emergencies or the one a month test I give them.

Recently there have been 4 new combined cycle plants built and or in start up. The smallest is 340 Mw. The largest is 2560 Mw.

Has your place ever looked into thermal storage solutions?

"Small" and "very small" are way more than enough to heat a house :-)

Nick

snipped-for-privacy@ece.villanova.edu wrote in news:dim9lm$js3 @acadia.ece.villanova.edu:

There's a reason it's called "waste" heat. For the most part, it's not very useful unless you've got a use for lots of low grade heat.

--Damon

You know, heating a home converts 100% of the gas or oil into "waste" heat in a furnace or boiler. Something I've kind of dreamed about for a long time is this: What if, instead of a furnace or boiler there was an engine and generator, the generator pumped electricity into the grid spinning the meter backwards (in many parts of the US this simply subtracts from your electric usage, at least until your monthly "usage" becomes negative, by law), and the "waste" heat from the engine/generator heated the house. It would be controlled by a thermostat as normal (when the "furnace" kicks on it generates heat for your house and electricity into the grid, when off it does nothing). Assume the furnace and engine/generator extract the same total energy from the gas/oil, and the electric generation is only 20% efficient. You'd use 5 gallons of oil when a regular furnace would use

4 gallons (remember you're using 80% of the fuel value as heat), but you'd generate however many kWh's worth of electricity that produces the same heat as 1 gallon of oil, and the electricity is worth more than the oil. Similar for gas.

Please, please do not misunderstand the following as an ad hominum attack:

Financial claims by a non disinterested party are to be taken with a grain of salt. Please open your books, so we can audit them in accordance with accounting standards.

Furthermore, even if your stated claim is correct, I claim that you are comparing apples to oranges.

The grid supplies universal service at a rather high level of reliability. Whereas, I have no data about how reliable your own generation is, and whether you could duplicate in 100 other residences, much less ten thousand. Perhaps you could, but I suspect your cost would be closer to 15 cents than 6 cents. In any case, we can say for sure that your home generation was SUBSIDIZED by your desire for it to happen. HAd you applied a normal cost-effectivity analysis to making it happen, you might not have bothered. IE, how many unpaid hours of time did you devote to making to happen, just for the ideological/afficianado erason of lovin' it? If you had to PAY yourself a normal engineering salary (with non-wage costs, such as taxes, benefits, etc), maybe your costs are HIGHER than those of the grid! And if you insist that we count the hidden costs (middle east wars, etc etc) of grid electricity, I insist that we count the hidden costs of home-supplied power. Is that unfair?

If you really have electricity that costs you less than a third of the grid, why aren't you smelting aluminum, or making ice for sale, or some other such enterprise where the major cost-component is the price of electricity?

you want to cherry-pick the electricity-demand.

it's easy to look cool, when you're allowed to pick and choose you requirements. If you suffer a grid outage, you'll be screaming for discipline against the utility. If your home system has a outage, uou'll just grin and bear it.

I can make a thousand dollars an hour. Just allow me to open a life-insurance or health-insurance company wherein I am allowed to cherry pick my customers. This is why college students have access to such low-cost health-insurance - they hardly ever have kidney failure, heart atacks, yadda, yadda yadda!

The electric utilities ***are** in a similar economic situation to an insurance company. they are required to serve all.

snipped-for-privacy@world.std.spaamtrap.com (Michael Moroney) wrote in news:din6ih$7ts$ snipped-for-privacy@pcls4.std.com:

During part of the year, I can see where all of the energy could be used; it's during the warmer part of the year that much of the engine's waste heat can't be used or usefully stored. Doesn't matter how efficient the engine may be, at least half of the fuel's original energy has to be wasted most of the time.

I don't see a breakeven most of the time; certainly it's never going to be better than what the utilties already accomplish with their generation systems.

Bottom line is that with a well-tuned diesel engine, your fuel costs are just going to be too high. And that's about the most practical generation there is for small, simple, energy systems.

The only way I can see home generation turning a profit is if you have a windy location, or even small scale hydro. Then the fuel is 'free', though the capital costs of recovering the energy and the practical problems associated with it may still be prohibitive. Few people are that lucky to have wind or hydro of any sort, too.

--Damon

Oh yeah! Just one example - we had a new generator added - had to be helicoptered in. I have *no* idea what that cost! Then there's hidden costs. For example, what is the value of the real estate occupied by generators/diesel fuel/maintenance area etc? I don't know the amortization period for the equipment, the cost of the concrete pads or their life expectancy, etc etc

In the single residence examples, the homeowner's man hours are never figured in - I supposed that is a hidden cost in that scenario. And I'll bet homeowner computations don't assign a value to the square feet used for generation (and related) equipment. At least, in the few examples I've read, I haven't seen it.

Not to my knowledge. But our generation is a peanut compared to yours, and we don't have much (any?) real estate to devote to thermal mass.

Ed

Some of the first co-generation plants in Sweden...reaching back to 70's or

80's, did just that.Used both the exhaust heat and coolant heat for the house.Think it had something on the order of a marine watercooled muffler to heat the coolant before it entered the house. And blowers in the house stripped enorgh heat to return it back to motor block.

Streching to remember the details from a "Popular Science" article.

>