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Comment by imgabe | Hacker News Reader

Instead of burning natural gas at the building, burn 5x as much at a power plant hundreds of miles away to generate electricity, then convert it back into heat at the building. Smart.

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Power plants are way more efficient, transfer loses are way exaggerated, and most of the energy will be soon provided by only renewable sources.

EDIT: and according to this [0], most of New York's electricity is already carbon free.

[0] https://www.eia.gov/state/?sid=NY#tabs-4

Power plants are more efficient at generating electricity, mechanical work, etc. than small generators. They are certainly not more efficient at generating heat than just burning the gas is.

Why not? When you use a stove, look how much of the flame is open, and take note of how much heat is being thrown off and not going into your food. When gas is burned in a plant, much more of that heat is captured.

But it’s really a moot point, because the goal is to change the power plants to clean energy sources anyway.

Quantify "way more efficient". How many cubic meters of natural gas do I need to burn to produce a given number of joules of heat at point of use vs. at a power plant?

It's not just transfer losses. The power plant has to heat water to steam, use the steam to turn a turbine. There's losses all along that process vs. directly using the heat where you want to heat something.

As has been mentioned elsewhere in this thread, until about 0 degrees F, electric heat pumps generate more BTU per watt than burning natural gas in your room.

And the power plant is far more efficient at capturing the heat than the furnace in your home or building.

A huge power plant that burns 5 times the amount of gas also generates more than 5 times the energy compared to you burning it at home at your stove. Especially for cooking it really surprised me that cooking with gas is still so common in the US. Here, basically every new house has uses induction which has become really accessible.

When it comes to gas for heating I'm somewhat indifferent. Even if the electricity is primarily from fossil source (which I don't know, but it is likely) I'd imagine it is a whole lot easier to continue improving the energy production to reach net-zero than it would be to wait and replace the gas heating in thousands of buildings.

The power plant burns the gas to heat water, which creates steam, which turns a turbine, which generates electricity which then gets turned back into heat at my stove.

The gas burned at my stove doesn't need 5 times as much because the heat from burning it goes directly into whatever I'm cooking on my stove.

I am very aware how natural gas energy plants work. However, your oversimplification of the process misses a crucial point. Many power plants improve their efficiency for example by providing district heating, etc.

Your stove is not only heating your pan, it also distributes a lot of heat into your room. And during summer you probably use quite a bit of energy to cool down your again. An induction cooktop is the most efficient type with somewhere around 80% iirc. Also, your electric cooktop can easily be supplied with carbon free electricity, while your gas stove will never be carbon neutral. Not to mention the possible health implications of an open flame burning natural gas while cooking.

Have you ever tried to hold your hand next to the edge of the pot..? A lot of the heat is not going into the pan.

Yeah, the same thing is happening at the power plant.

It’s absolutely not.

I can't speak to the relative efficiency, but central power generation is much easier to upgrade (both in terms of scrubbing the emissions and switching to renewables).

A lot easier to switch to renewals with electricity. I don’t know of a way to do that with natural gas.

A lot of gas distribution networks are experimenting with hydrogen blending (adding a % of sustainably generated hydrogen to the methane blend), much the same as adding ethanol to petrol.

However, beyond the engineering issues (existing pipes not always suitable for hydrogen blended gas) it just kicks the can down the road and delays the structural changes needed to get households away from using natural gas.

Only a few are doing full % hydrogen conversions, City of Leeds being the biggest project under way.

That sounds interesting, how are they managing the invisible nature of hydrogen flames?

There's [1] but I'm not impressed by the efficiency numbers.

Also, no need to go through electricity. Significant part of my city is heated by waste heat of power plant that would otherwise go out the cooling tower.

[1] https://en.m.wikipedia.org/wiki/Power-to-gas

Couldn't they just cut off the gas and switch to electric once the power plants are clean(-enough)?

NYC already has relatively low-CO2 electricity and is signing an agreement with hydro Quebec to keep things that way.

No, you need to transition over time.

Your idea is to just cut off the gas one day, and expect everyone to go out and buy new appliances at the same time? I don’t think I need to explain why phasing in such a change is preferable.

I don't expect to just cut it off all of a sudden. They could announce the cut some years in advance.

Of course, if right now they already expect to cut off the gas a few years from now, they may as well not build new pipes.

According to my power bill, 50% of electricity in my Brooklyn apartment comes from nuclear generation, about 25% from hydro and solar, and the remaining 25% from fossil fuels, mostly natural gas.

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