Electricity or gas?

The energy crisis is probably the main topic of today. Although gas-fired furnaces are cheaper to operate, under the pressure of external events, their era seems to be slowly coming to an end. However, I have already heard that some heat treaters have started converting furnaces from gas heating to electricity heating. It makes sense?

Fig. 1 – The elektricity price on the stock exchange

Fig. 2 – The natural gas price on the stock exchange

The pictures show the prices for electricity and gas from July 29, 2022. The graph shows that both commodities develop in complete agreement. It makes sense, a large part of electricity is produced from gas. Therefore, the ratio between them does not change much. Therefore, if the exchange of gas for electricity should make sense, it must have advantages other than price.

If we were to compare them in terms of price per 1 kWh, then electric energy is more than 3 times more expensive than gas. But this is not a condition we are not familiar with. If I look at my data from 2014, the gas price was € 0.033/kWh and the electricity price was € 0.103/kWh. Although both values are final prices including distribution, ecology, etc., and therefore do not directly correspond to stock market prices, the ratio is again 3:1.

So the problem lies elsewhere, primarily in expectations. The confidence index in CZ has fallen to a minimum and is the lowest since 2003. However, confidence in the fact that there will be any gas at all has also fallen.

Fig. 3 – The business climate index in CZ

Because the Czech Republic receives natural gas indirectly, through Germany, if there is no gas in Germany, it will not be here in the CZ either. And that is probably the reason why some have started to refurbish furnaces from natural gas to electricity.

However, it seems to me personally not a well-considered investment. It follows from the logic of the matter that if there is no natural gas, there will be no electricity either. Although we will have a “greener” oven, this is not entirely true either.

Back in 2015, AFC Holcroft’s Jack Titus on the Thermal Processing website publishes, I quote:

Natural gas (methane) is the cleanest burning fuel besides hydrogen, liberating only CO2 and water vapor from its combustion  https://thermalprocessing.com/hot-seat-7/

It is a myth that green plants and trees convert CO2 into oxygen, but they do consume CO2. In simple terms, oxygen is produced from green plants and trees as the result of the reaction of water vapor (H2O) and daylight during photosynthesis. Also, CO2 reacts to form sugars within the plants. So, both water vapor and CO2 produced by the combustion of natural gas are not a detriment but are helpful to a healthy atmosphere. It has been said that if hydrogen today replaced all of the natural gas burned and totally eliminated all of the CO2 entering the atmosphere, that CO2 dissolved in the oceans and lakes would reenter the atmosphere to regain natural equilibrium

According to the first law of thermodynamics, the total amount of energy (of all kinds) of an isolated system remains conserved, or it is not possible to construct a machine which would continuously supply mechanical energy without consuming a corresponding amount of energy of another kind.

This also applies to heat treatment. The amount of energy that we need to get into the furnace or isolated system is the same for both gas and electricity. And it doesn’t matter if we produce the carbon footprint directly at the furnace directly under our control, or at the power plant, where we don’t know at all whether this energy is green or black.

Information can be found at this resource https://www.heattreattoday.com/equipment/heat-treating-accessories/burners-combustion-systems/burners-combustion-systems-technical-content/future-heating-of-industrial-furnaces/, that by using suitable burners we achieve emissions of 0.25 kg CO2/1 kWh, while electric energy from power plants in Germany or the USA is somewhere around 0.45 kg CO2/1 kWh.

Therefore, saving energy on the existing system is more important than replacing the energy source. And the fear that there will be no natural gas at all? If this were to happen, it wouldn’t matter at all if the furnace is electric or gas. There will be no reason to use it at all.

July 31, 2022

Jiří Stanislav