Going 100 percent renewables is gaining momentum
By Drs. Robert & Sonia Vogl
President and Vice President,
Illinois Renewable Energy Association
As of this February twenty-three American cities have committed themselves to utilize 100 percent renewable energy. Moab, Utah intends to reach its goal by 2032. The renewable energy revolution is global in scope.
Andrew Blakers, an Australian energy engineer, reminds us that wind and solar are already cost competitive with fossil fuels. They will become even cheaper as their manufacturing achieves enormous economies of scale. He estimates Australia can meet 50 percent of its electrical needs with renewable energy sources without building any new backup capacity.
Improved weather forecasting allows us to know a day in advance how much wind and solar output will be available. If reductions in demand are required, contractual load sharing, using existing coal and gas generators to pump additional water into elevated hydro storage reservoirs and controlled charging times for EV batteries can be implemented.
It is relatively easy to install heat pumps in urban areas to meet heating and hot water demand in buildings, provide large scale energy storage in batteries of electric vehicles and utilize the thermal inertia in water and buildings. Battery storage can occur at different sites including homes, businesses and adjacent to wind and solar farms to stabilize the electrical output from the installations.
Renewable energy sources alone will not solve the climate problem. It will require other measures including curtailing demand and capturing and storing carbon. The transition to renewable energy sources and electric vehicles will increase demand for metals and minerals. Securing them has adverse environmental impacts which will need to be managed.
A homeowner with a solar system and a modest amount of battery storage could provide a couple of days of power during cloudy weather. The batteries could be charged at night at a low cost and the electricity sold back to the grid at a higher price during times of peak demand. An owner of an electric vehicle such as a Nissan Leaf could draw power from the vehicle’s 24 kWh battery capacity to serve as backup power.
Blakers describes an off-river pump storage system which could provide an additional source of electricity. It involves the creation of two hectare sized reservoirs, one at the river and another at least 200 meters above the first one with a pipe to carry water up and down the incline. The stored water would be released during times of high electrical demand to generate electricity and replenished using electricity during times of low demand.
If the system performs as projected it could be applied to other areas with substantial river flows and sufficient elevation differences to provide backup power to meet peak demand.
If Australia installs wind and solar systems at a rate of 1 GW each year starting in 2020 as projected they could meet 40 percent of their energy needs with renewable energy sources by 2030. By installing 2 GW of wind and solar annually they could meet 80 percent of their needs, or 94 percent if they installed 2.5 GW/year by 2030.
Wind, solar and heat pumps are also cost competitive in many parts of the United States. Steve Hanley states that Ward’s Auto reports EV battery prices are falling more rapidly than expected and could be lower than $100/kWh by 2020. At that price the cost of electrical propulsion is slightly less than the cost of propulsion via an internal combustion engine. Falling battery costs will make the option of battery backup systems more appealing to homeowners with PV systems.
The cost reductions of renewable energy sources and batteries result from successful research done a decade ago. Over this next decade another wave of successful research projects will be integrated into commercial renewable energy projects accelerating technological improvements and falling costs.
As many others have pointed out, the technology is ready. The challenge is implementing it.