A new paper: 100% clean and renewable wind, water, and sunlight (WWS) all-sector energy roadmaps for the 50 United States by Jacobson et al 2015 describes the wind, solar and other renewable technologies needed to supply all the energy used in the USA That is all the energy, not just the electricity. They find that using wind to generate 50% of energy, solar photovoltaic (PV) for 38%, concentrated solar power (CSP) for 13% and a combination of hydro, geothermal, tide and wave power for the remainder (5%) allows all energy in the USA to be supplied at a lower cost than using fossil fuels. (The total is over 100% as extra power is required to stabilize the power grid because the wind does not always blow and the sun does not always shine).
Fig. 5 (from Jacobson et al 2015) Time-dependent change in U.S. end-use power demand for all purposes (electricity, transportation, heating/cooling, and industry) and its supply by conventional fuels and WWS generators based on the state roadmaps proposed here. Total power demand decreases upon conversion to WWS due to the efficiency of electricity over combustion and end-use energy efficiency measures. The percentages on the horizontal date axis are the percent conversion to WWS that has occurred by that year. The percentages next to each WWS source are the final estimated penetration of the source. The 100% demarcation in 2050 indicates that 100% of all-purpose power is provided by WWS technologies by 2050, and the power demand by that time has decreased.
The jobs required to build and run the renewable power supply would be greater than the jobs lost by closing down the fossil and nuclear power suppliers. About 0.42% of land would be covered by the generators. An additional 1.6 % of land would have wind generators spaced widely. The land in between could be used for farming or other uses.
This paper quantitates the work required to bring carbon emissions down to zero and shows that it can be done in a cost effective manner. There are few technical barriers that need to be overcome to implement this proposal. The primary issue is lack of political will.
For this paper Jacobson et al set up enough renewable generators in each of the 50 states to generate all the power needed for that state. A separate grid integration study (just accepted for publication in the Proceedings of the National Academy of Science pending minor revisions) details the grid interconnections needed to provide 24/7 power coverage for all the states. Since renewable energy varies over the USA, a stronger grid is required to ensure everyone has enough power all the time.
Jacobson et al. have previously developed roadmaps for California and New York This paper expands on that previous work and shows that all 50 states can generate the power they require. Jacobson et al have developed similar roadmaps for many countries and for the globe as a whole.
They followed this procedure:
“The methods used here to create each state roadmap are broadly similar to those recently developed for New York, California, and the world as a whole. Such methods are applied here to make detailed, original, state-by-state estimates of
(1) Future energy demand (load) in the electricity, transportation, heating/cooling, and industrial sectors in both a business-as-usual (BAU) case and a WWS case;
(2) The numbers of WWS generators needed to meet the estimated load in each sector in the WWS case;
(3) Footprint and spacing areas needed for WWS generators;
(4) Rooftop areas and solar photovoltaic (PV) installation potentials over residential and commercial/government buildings and associated carports, garages, parking lots, and parking structures;
(5) The levelized cost of energy today and in 2050 in the BAU and WWS cases;
(6) Reductions in air-pollution mortality and associated health costs today based on pollution data from all monitoring stations in each state and in 2050, accounting for future reductions in emissions in the BAU versus WWS cases;
(7) Avoided global-warming costs today and in 2050 in the BAU versus WWS cases; and
(8) Numbers of jobs produced and lost and the resulting revenue changes between the BAU and WWS cases”
In a previous study (with 593 citations!) Jacobson identified the WWS methods that were most cost effective. Nuclear, coal with carbon capture and biofuels were found to not be as effective as the methods evaluated in this paper for various reasons.
Wind generators would produce about 50% of power in the USA according to Jacobson's proposal.
Jacobson et al describe how industrial processes will be electrified. For example iron can be produced using electric arc furnaces instead of current coal powered blast furnaces. Some technologies need to be developed, for example they project using cryogenic hydrogen to power airplanes and hydrogen fuel cells and electricity to power ships. This raises demand for electricity but removes all fossil fuel use. All states use much less overall power because electricity is more efficient than internal combustion engines and boilers (for example the boilers in coal and nuclear plants are only 33-40% efficient, cars about 25%).
They calculate the number of generators required by each state. For example, Florida has little hydro power resources but good solar while Washington has large hydropower and good wind. They estimate how many solar panels can be installed on top of buildings. Other land uses are calculated based on the WWS resource used. They compare the amount of land required to generate the power with the available land resources and find that the USA has large excess capacity for wind and solar power. Hydro power, which is the most flexible WWS power, is more limited. Tidal, wave and other resources are very small. They discuss the potential of each of the types of WWS power. Click here for an interactive map of the power sources for the 50 states.
Many of the costs for fossil fuels are currently borne by taxpayers. In addition to production subsidies, fossil fuels cause billions of dollars yearly in health costs and damages from their pollution. The climate costs are already measurable and will increase in the future. Acid rain, mercury and arsenic pollution are costs the public bears. These costs are estimated and counted as part of the final cost of energy.
A section of the paper estimates how many jobs will be required to install and maintain the WWS resources. This is compared to the current jobs in the fossil fuel and nuclear industry. They find that many more jobs will be created by WWS energy than lost from the fossil fuel industry.
They suggest that if we got serious about avoiding damage from climate change we could eliminate 80% of carbon dioxide emissions by 2030 and 100% by 2050. That would require substantial effort, but compared to the effort in manufacturing military hardware in WW2 it is a doable task. Reducing energy use by more sensible building codes and more efficient use of energy is discussed. Obviously it is easier to make all energy needed if less energy is required.
They discuss the priority of electrifying different industries. Electric cars will be easier to manufacture (since they are already in production) while hydrogen airplanes will require more work.
This is a conservative estimate of the cost of building of a power system for the USA. If the generators were put in the most efficient places, instead of each state generating its own power, it would be substantially cheaper to build the system. Since Florida currently imports coal to supply much of its electricity, why not import electricity from wind generators in Texas in the future?
The paper ends with this summary:
“Based on the scientific results presented, current barriers to implementing the roadmaps are neither technical nor economic. As such, they must be social and political. Such barriers are due partly to the fact that most people are unaware of what changes are possible and how they will benefit from them and partly to the fact that many with a financial interest in the current energy industry resist change. However, because the benefits of converting (reduced global warming and air pollution; new jobs and stable energy prices) far exceed the costs, converting has little downside. This study elucidates the net benefits and quantifies what is possible thus should reduce social and political barriers to implementing the roadmaps.”
This paper shows that it is possible using technology currently manufactured to generate all required energy for an economy like the USA. Standards of living do not have to be lowered to achieve sustainable energy. There is no technical reason not to pursue WWS energy. Unfortunately, the recent article on SkS about the Koch brothers suggests there will be more political problems than technical issues actually implementing a solution.
Posted by michael sweet on Thursday, 20 August, 2015
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