Tag Archives: solar

Sustainable Energy is Booming

By late in 2019, the combined electricity produced by grid-connected wind and solar photovoltaics represented 10% of the total production. And the share of these intermittent but sustainable energy sources continues to grow. Energy production from coal is in free fall, despite the current administration’s attempts to favor it.

A constant refrain from detractors is intermittent sources such as wind and solar require expensive backup when the wind isn’t blowing or the sun isn’t shining, and therefore can’t be a serious part our electricity production until such batteries or other energy storage systems are available. That however is just not the case. It is estimated that a national network of electricity production and distribution can utilize up to about 30% wind and solar without the need for additional storage to back up the intermittency.

Consider what happens when one of our local nuclear reactors goes down to refuel. Is there another reactor on stand by to make up for the power not produced during the refueling? No, of course not, there is plenty of “slack” in the system to make up for that not produced during the refueling.

Other factors help balance the power from wind and solar. Solar is well matched to demand. Demand is higher during the day when solar panels are producing, and lower at night when the power from solar panels isn’t needed. Without the input from solar panels, a power company may have to buy power from sources that are on standby. Some power companies utilize time-of-day pricing, charging less at night when power is relatively abundant, and more during the day when demand is higher.

Wind and solar also balance each other seasonally. As sunlight passes through the atmosphere light is scattered and less reaches the earth. The lower the sun angle the more atmosphere it must pass through. Solar panels are more productive in the summer due to the the higher sun angle. A higher sun angle means less scattering of the light and more sunlight striking the panels.

Conversely, wind turbines are more productive in the winter. There are two reasons. Wind is generated by temperature differences between locales and the differences are greater in the winter, hence higher wind speeds. Additionally, colder air is denser. More power will be generated by the denser air at a given wind speed.

One final balance is that the sun shines during the day (duh) so solar power is available during the day, but wind speeds are greater at night. Wind and solar are both intermittent but complementary, both daily and seasonally.

As intermittent energy sources grow there will be a need in the future for energy storage and that constitutes a huge area of research. Electrochemical batteries, pumped water storage, other gravitational energy storage systems, compressed air, flywheels, and on and on. The future will be powered by the wind and the sun, cleanly without the need for fuel, and without waste disposal issues.

Dr. Bob Allen is Emeritus Professor of Chemistry, Arkansas Tech University.

Wrong Way President

Republicans have long been known as the party of business, both big and small. The party that believes in the free market. The party that doesn’t want government picking winners and losers. The GOP platform statement is unambiguous. “Government should not play favorites among energy producers.“

Recently Trump has floated a plan to order the electrical grid operators to buy power from coal and nuclear powered electrical generators. Even though power from natural gas-fired plants is cheaper and cleaner. Even though power from wind turbines and utility-scale photovoltaic systems(solar) is far cleaner and now cheaper than coal-fired plants.

His argument which will drive up the cost of electricity is a somewhat poorly disguised attempt to prop up industries whose time has past. Twenty-five coal plants have closed since he began as president. The two largest coal plants here in Arkansas are in negotiations for closure within a decade. There hasn’t been a new order for a nuclear plant in several decades.

Meanwhile, wind and solar power are rapidly expanding. Clarksville just added its own solar array and Entergy is building two major solar plants.

The plan to help the coal and nuclear industries is couched as a national defense emergency, and if this order were to be enacted would employ a regulation normally used to respond to national crises such as weather-related disasters.

Coal and nuclear plants are referred to as baseload plants. They’re designed to be turned on and stay on, at full power. It is Trump’s position that replacing these baseload plants with renewables will somehow make the electrical grid less resilient.

Nope. Numerous studies show that a broad mix of renewable energy supplies on the grid leads to greater stability. Two countries, Germany and Denmark, have far larger percentages of their electrical energy generated by wind and solar and have an order of magnitude fewer outages than the United States. This may be in part due to better investments in the grid infrastructure, but it certainly shows that renewables don’t hurt.

The people who really know what’s best are the grid operators themselves. They view today’s grid in better shape than ever in terms of reliability. Trade groups for the oil and gas industry joined with environmental groups to issue a joint statement claiming that the plan was legally indefensible and guaranteed to raise the cost of electricity to consumers.

A similar but more subtle plan was pursued last year by Rick Perry, administrator of the Energy Department. Perry requested the Federal Energy Regulatory Commission (FERC) to guarantee a financial return for any power plant that could store on site ninety days worth of fuel. This would, of course, mean coal and nuclear plants. The FERC earlier this year unanimously denied the request.

Trump, the purported deal maker, would be in this case increasing the cost of electricity for consumers. He would be reversing the trend towards cleaner air and lower greenhouse gas emissions. And finally, the plan would only make worse the problem with high-level radioactive waste, an issue we haven’t been able to resolve after sixty years of commercial nuclear power production.