Clean and green

The world is experiencing unprecedented fuel price increases, energy blackmail between countries, up to 7 million air pollution deaths per year worldwide and one climate-related disaster after another. Critics contend that a switch to renewable energy to solve these problems will create unstable electricity grids and drive prices up further. However, a new study from my research group at Stanford University concludes that these problems can be solved in each of the 145 countries we examined – without blackouts and at low cost using almost all existing technologies. The study concludes that we do not need miracle technologies to solve these problems. By electrifying all energy sectors; producing electricity from clean, renewable sources; creating heat, cold, and hydrogen from such electricity; storing electricity, heat, cold and the hydrogen; expanding transmission; and shifting the time of some electricity use, we can create safe, cheap and reliable energy everywhere.

The biggest reason for the cost reduction is that a clean, renewable energy system uses much less energy than does a combustion-based energy system. In fact, worldwide the energy that people actually use goes down by over 56 percent with an all-electric system powered by clean, renewable sources. The reduction is for five reasons: the efficiency of electric vehicles over combustion vehicles, the efficiency of electric heat pumps for air and water heating over combustion heaters, the efficiency of electrified industry, eliminating energy needed to obtain fossil fuels, as well as some efficiency improvements beyond what is expected.

On top of that, a new system also reduces the cost per unit energy by another 12 percent on average, resulting in a 63 percent lower annual energy cost worldwide. Adding onto that health and climate cost savings gives a 92 percent reduction in social costs, which are energy plus health plus climate costs, relative to the current system.

The energy-producing technologies considered include only onshore and offshore wind electricity, solar photovoltaics for electricity on rooftops and in power plants, concentrated solar power, solar heat, geothermal electricity and heat, hydroelectricity, as well as small amounts of tidal and wave electricity. The most important electricity storage technology considered was batteries, although pumped hydroelectric storage, existing hydroelectric dam storage and concentrated solar power electricity storage were also treated. We found that no batteries with more than four hours of storage were needed. Instead, long-duration storage was obtained by concatenating batteries with four-hour storage together. In a sensitivity test, we found that even if battery prices were 50 percent higher, overall costs would be only 3.2 percent higher than their base estimate.

We also considered seasonal heat storage underground in soil plus short-term heat storage in water tanks. Seasonal heat storage is useful for district heating. With district heating, heat is produced and stored in a centralized location then piped via hot water to buildings for air and water heating. The alternative to district heating is using heat pumps in each building. The study found that the more district heating available, the easier it was to keep the electric grid stable at lower cost since it reduced the need for batteries to provide immediate electricity to heat pumps. Batteries are more expensive than underground heat storage.

Excerpted: ‘We Don’t Need Magic Technologies for Renewable Energy Transformation’.

Courtesy: Commondreams.org