#11 — Why Don’t They Just…
Most of the buzz about renewable energy is focused on solar and wind power. But our planet is blessed with many sources of renewable energy, and I often get questions like: “There is so much _____ energy! Why aren’t we using that?” Let’s try to fill in a few of those blanks.
HYDROPOWER
Until very recently, dams and the reservoirs behind them were the biggest source of renewable energy on the planet. So why don’t we build lots more? Hydropower will continue to be a major source of electric power, but expanding it is problematic. Most of the sites with the greatest potential (large rivers flowing through the kind of topography that lends itself to big reservoirs) are already developed. On sites that offer smaller potential, concerns about wildlife habitat, population relocation, and silt accumulation often negate many of the advantages of developing such sites.
GEOTHERMAL
We all learned in grade school that the center of the earth holds a great deal of heat. In some places this heat is very close to the surface and can be easily accessed as a clean energy source. In a few places, enough energy can be harvested to generate electricity. The US leads the world in geothermal electricity production. But locations with this kind of potential are rare, and already largely developed.
But there is another type of geothermal heat that holds much greater potential. Only 6 - 10 feet below the surface, the soil stays at a relatively constant 45 to 55F the year round. Although this heat is diffuse, there is a tremendous amount of it, and heat pumps can be used to concentrate it and send it into our chilly living rooms. Even better, the same heat pumps can be used to take heat out of a sweltering summer living room and put it back underground!
WAVES & TIDES
There is a staggering amount of energy delivered to our shores every day in the form of tides and waves. If we could harvest it all, we wouldn’t need anything else. But it’s not easy:
Most of this energy is in the oceans — oceans have salt, salt is corrosive, and engineering and building mechanisms to deal with that is expensive.
As anyone who has lived through a hurricane or New England Nor’easter can attest, our shores are often subject to some pretty harsh conditions. Building machines to deal with that is even more expensive.
A fearsome array of opponents would rise up like the soldiers born of dragon teeth in Greek mythology: boaters, fishermen and NIMBY shorefront property owners. Added to the other costs, this technology will likely have to wait a while.
BIOMASS
Prior to 1850, virtually all our energy came from biomass. Today’s biomass energy sources include forest products (around 40%), biofuels (mainly ethanol from corn, around 40%) and municipal waste (burning trash and biogas from land fills and sewerage treatment facilities, almost 10%).
Maine is the most forested state in the Union and already gets a substantial percentage of its power from this source. But Maine’s forests are already used intensively for other purposes, like paper and lumber. Good forest management is critical to this approach, otherwise otherwise it just becomes another source of extra carbon in the atmosphere.
At this stage of the climate crisis, I believe that we should be growing more trees (to absorb and store CO2 from the atmosphere) rather than cutting more down for fuel. Ethanol from corn is a very questionable way to produce energy. Energy from biomass will continue to be an important energy source, but can’t be expanded enough to make up even a small percentage of our dependence on fossil fuels.
For a deeper dive:
The US Energy information Agency has good basic information on the state of tidal power and links to some demonstrations projects. Tidal Power
Corn based ethanol fuel is a favorite of politicians. Not so with the scientific community. Reuters
AND THE WINNERS ARE…..
Photovoltaic panels and wind turbines have the huge advantage of being mass producible. We all know about what mass production has done to TV sets in the last 20 years — they’ve gotten lots bigger, much better and far cheaper. Photovoltaic production has increased more than 1000% since 2010, and the price has fallen by 86%. In a decade, install wind power went from 2.4 to 118 million kW, with a price reduction of 70% per kW. During the same period there has been little increase in the other renewable sources. Electricity from wind and solar is now cheaper than from fossil fuels.
SO……
Hydropower and biomass will continue to provide valuable renewable power. Ocean and geothermal energy hold great promise. But wind and solar are the tools we have available right now, and time is of the essence!!
Thanks for reading,
Doug Hylan, Brooklin, Maine
“The world that you and I live in is increasingly challenged. Population growth, pollution, over-consumption, unsustainable patterns, social conflict, climate change, loss of nature… these are not good stories.” – Jack Dangermond