Hacker News Reader

Comment by treflop | Hacker News Reader

Batteries aren’t just used in cars man.

Really hard to beat propane or diesel for heat in the wilderness right now.

We don't have billions of people living in the wilderness. And technology has reached a price level where off-grid solar is actually an affordable and superior alternative to propane and diesel for household use in rural Africa.

Heat pump heat, in the wilderness or otherwise, is about 4x as efficient as resistance or fire.

This is somewhat silly, since a gas-fired heat pump can be very efficient, but gas-fired heat pumps are quite rare.

(California has a pricing/policy problem here, IMO. Electricity is absurdly expensive, gas is somewhat reasonable, and the result is that electric heating is not nearly as economical as it should be.)

Gas-fired heat pumps are neither economical nor efficient for single-apartment or single-house systems. Internal combustion engines with shaft power output of 1-2 kW are inefficient, loud and maintenance intensive.

They can start to make sense from around 50 kW heating/cooling capacity and upwards, so the smallest units are suitable for 8-15 apartments depending on size.

Yeah but the article is just about batteries and someone asked to see a graph about energy density.

Plus they asked about airplanes and somehow you made it about cars.

The person you are responded to did not make it about cars. They were responding to someone talking about cars

“Heat in the wilderness” must be so small in terms of global emissions footprint to be almost irrelevant, no? The wilderness implies ultra low density sort of by definition.

Reply on news.ycombinator.com