This article began as a short answer to a simple question: “Heating water: What’s less costly? Natural gas, electric stove top, or microwave? The answer may surprise you!”
With my natural tendency to dig far deeper into things than most journalists, aided by an overabundance of curiosity, combined with extensive education and experiences in various disciplines including engineering, science, and business (finance), I wound up writing this much more thorough article, instead.
But first, since it is indeed such an interesting topic, we’ll cover the original question, first, as it leads straight in to the main topic.
If you jumped right to microwave, thinking it’s more efficient than anything, well, that’s not true. Whether by wind, solar, hydroelectric, tidal, natural gas, oil, or nuclear, the electricity must first be generated. This results in a number of different loses, including extraction, manufacturing, construction and conversion, depending upon the means of electrical production. Then the electricity must be moved from the location of its generation to your home, resulting in transmission losses. Finally, there’s another conversion loss from electrical energy into microwaves, and that final conversion is only about 60% efficient.
By comparison, the resistive element in a modern electric hot water heater ranges between 90% and 95% efficient.
Modern stove tops use either gas, resistive element, radiative heating (IR) and induction, and they’re all more efficient at converting electricity into hot water than your microwave! Let’s examine:
- Microwave: 50%
- Electric Burner Stove: 70%
- Electric Teakettle: 80%
- Induction Stove: 85%
Using a proper tea kettle (thin walls, large, round copper bottom, curved sides), boiling, say, a liter of water on top of the stove costs less than boiling it in any microwave-safe container in your microwave.
When it comes to the cost of heating a liter of water, however, natural gas wins hands-down. This is because on a per-BTU applied to the contents of the tea kettle, natural gas costs between a third and a half of any of the electric means mentioned above.
When it comes to hot water heaters, electric hot water heaters have a very high conversion efficiency due their immersed heating elements. Even so, natural gas still edges out electric in terms of cost, primarily because there are very small per-BTU conditioning costs for natural gas, low transmission costs, and no conversion costs before it’s burned to produce heat. Even so, the efficiency of gas hot water heaters is only about 62%. Gas makes up for the difference in cost because it’s so much cheaper per BTU than electricity. In fact, gas hot water heaters range between 45% and 55% the cost of heating the water as do electric hot water heaters. Same goes for heating your home. Using a gas furnace is much cheaper than electrical heat.
When it comes to the cost of producing electricity, however, gas has apparently met its match. Check out the latest cost figures for various types of electrical production. Solar photovoltaic (solar panel), onshore wind, combined cycle (gas-fired steam turbine with heat recovery steam generation (HRSG)), geothermal and hydroelectric all manage to slide in below 40.
Obviously, at two to three times the cost of onshore wind, offshore wind is about as stupid a solution as one can get! If you’re a member of a government who allowed offshore wind manufacturing companies to sell you this incredible rip-off, shame on you! Go soak your head. RESIGN, as you’re not serving the needs of your people at all! Biomass is equally stupid. If you backed the biomass solution, FIRE yourself for being an environmental idiot.
No doubt Greta supports offshore wind — by far the absolute worst choice — based upon mindless, agenda-driven illogic alone.
Now, here are the PROBLEMS:
- natural gas (combined cycle) is a limited and irreplaceable source of fuel
- solar voltaic only lasts for 15 to 30 years
- geothermal and hydroelectric are limited in availability
- advanced nuclear is plagued by perhaps well-intentioned but otherwise blitheringly idiotic greenies
- biomass is heavily limited, a blind, bumbling, stumbling, ignorant choice heavy on idealism, driven by agenda but way short on actual fact
- offshore wind is a total scam, a massive ripoff
So… Where do we go from here?
First, the fact capacity weighted average cost for all sources except combustion turbine is at or below simple average tells me economies of scale hold true for most electrical power generation.
Second, knowing all modern gas production of electricity is via combined cycle tells me that smaller, older combustion turbines have been maintained and are likely inverting the economies of scale. Put simply, it’s a reflection of older installations, not that smaller is better. Regardless, when it comes to using gas to produce electricity, combined cycle is the way to go.
Third, let’s just toss the idea of “developing” the most expensive options like offshore wind and biomass. We’re not putting all our eggs in one basket by going with the other seven viable options. Those are plenty of options.
Fourth, develop the cheapest renewable options, first:
- solar photovoltaic
- onshore wind
Fifth, develop the non-renewables to provide base loads:
- ultrasupercritical coal
- advanced nuclear
Sixth, stop building houses that suck. R-15 walls? Please… My uncle built his own home. He had R-50 walls and an R-75 ceiling, airtight with both inward-facing and outward-facing IR reflection and half a dozen similar improvements. His year-round utility bills in his 4 BR, 2.5 BA home were less than a third of mine in my “modern” U.S. home. U.S. homes suck.
Seventh, our national grid requires DC isolation. High-voltage direct-current (HVDC) technology is used for greater efficiency over very long distances (typically hundreds of miles). HVDC technology is also used in submarine power cables (typically longer than 30 miles (50 km)), and in the interchange of power between grids that are not mutually synchronized. Trying to maintain synchronization over multiple grids is problematic. A/C transmission over long distances incurs high rates of impedance due primarily to inductance. There’s no inductance with DC. EMP surges can easily overwhelm synchronization of A/C grids. Very long runs of DC has its own capacitance, which provides natural attenuation of EMP surges.