AboutBill Mihalovits Expertise I can answer questions about general construction and safety of plants, specific questions about operations, training, reactor theory, and thermodynamics. Will also consider other aspects as requested.
Experience Over 33 years in the nuclear power field, licensed senior reactor operator, and instructor.
Question QUESTION: Hi, I'm starting in the energy industry and have been hearing a lot about coal vs. gas vs. nuclear for generating electricity.
Can you explain the relationship between heat capacity for each of the above fuels & how they relate to much it costs to make the electricity? I can't seem to grasp the concept. Also do the various technologies of these items have different efficiencies & if so how does it affect the electricity? Thanks.
ANSWER: Sorry that I couldn't answer yesterday. My laptop wouldn't stay logged onto the internet last night, then the hotel lost power early this morning and was without power all day (except on the first floor, supplied by an emergency diesel generator). I'm home now, and will attempt to answer your questions.
Coal produces the least amount of heat per unit of volume. Coal itself is relatively cheap and the mix of the these two factors makes it the middle priced source of power in terms of price per kilowatt.
Gas is more efficient, producing more energy per unit of volume, but also more expensive. It's the most expensive of the three.
Nuclear is the cheapest. The cost of fuel is very high, but a single pellet of enriched uranium fuel provides as much energy as several tons of coal.
I wish I could find some actual numbers right now, but I'm finding zip on the internet and I'm not at work to access the numbers there.
The efficiencies of these plants contributes to the cost per kilowatt (actually measured in kilowatt or megawatt per hour). Nuclear is the most efficient and cheapest, gas is more efficient (I think) but the higher cost outweighs the gain in efficiency, making it the most expensive; coal is least efficient, but the cheaper cost puts it in the middle.
A generator doesn't care what turns it, the electricity is the same whether it's from a hydroelectric plant or any other source.
Did I answer your questions?
If I can find the numbers for cost per kilowatt-hour tomorrow, I'll post it here.
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QUESTION: Does this mean coal has a low heat capacity and the other fuels have high heat capacity (energy per unit of volume)?
Answer Yes. Coal has the lowest heat capacity, followed by natural gas. Nuclear fuel has the highest heat capacity.
Bear in mind that there are different grades of coal, some have higher heat capacities than others. But in any case, you get more energy per unit volume out of gas (assuming compressed gas).
It get's tricky when you're talking about volume, because gas can be compressed to various pressures, decreasing the volume per unit of mass.
