Is solar power the answer to all of our prayers? Or will wind turbines continue to play an important role in our energy future? Two HBS students from the Energy and the Environment Club debate this critical issue.
Solar is the Future of Renewable Energy Generation
by Evan Hindman (OI)
With the rise of atmospheric carbon and the depletion of finite reserves of natural resources, it is clear that our energy future will inevitably have a larger percentage of renewable energy generation in the total energy mix than exists today. However, of the two dominant sources of renewable energy currently deployed, wind and solar, solar has some distinct advantages over wind that convince me that the US and the world should be aggressively pursuing increases in installed solar generation capacity.
Solar is modular: A single solar panel is about the size of a standard coffee table, making panels easy to transport, install and use in projects ranging from just a few kW on a residential rooftop to hundreds of MW in the middle of the Nevada desert. Modern wind turbines have blade lengths of 50 meters or more, creating substantial transportation and installation difficulties.
Solar produces its maximum power output exactly when it is needed most: Solar panels produce the most power on hot, sunny days – exactly when the need for electricity is highest (primarily to run air conditioning). Solar can therefore be a cost-effective replacement for expensive gas or diesel peaker plants that remain idle for 90+% of their asset life. Wind, on the other hand, generally produces the most power at night, when the demand for electricity is lowest.
Solar is cheap, and getting cheaper: Prices for solar panels have been decreasing exponentially replica breitling, dropping from an average of $3.50/W in 2008 to just over $1.00/W today. The US SunShot initiative aims to decrease that by at least another 50% by 2020, which would make large-scale solar installations cost-competitive with today’s cheapest and dirtiest coal plants. Prices for wind turbines, on the other hand, have been flat or increasing since 2000, according to the US Department of Energy.
There are few siting concerns with solar power: Wind turbines are big, loud, and kill birds. Solar panels are small, silent, and have no moving parts. It should come as no surprise, then, that countless wind projects have been held up or cancelled due to opposition by local citizens. (The Cape Wind project is just one high-profile example of this). Solar has faced little to no community backlash.
There is only one true renewable energy resource on Earth – the sun: Every source of fuel on earth – including fossil fuels – ultimately originated as electromagnetic radiation from the massive nuclear reactor 93 million miles away. Even wind energy is created by the sun via pressure differentials of hot air moving from one region to another. Total global electricity demand could be met by collecting just 0.000001% (yes, five zeroes) of the direct solar radiation the earth receives every year. Doesn’t it make sense to start harnessing that energy directly?
Why Wind Energy Should not be in Solar Shadows
by Sylvain Mansier (OF)
The recent growth in installed solar energy capacity in the U.S. (over 100% increase in 2010) has sparked significant interest in solar energy potential, seemingly relegating wind energy to a diminished ‘stepchild-like’ status. The solutions to our energy challenges should include a diversified portfolio approach, however, and the relative benefits of wind energy should not be ignored. Although solar panel cost curves are declining, wind energy still delivers a less expensive source of power. What’s more, continuing innovations with wind turbine generators are leading to improvements in efficiency and productivity factors, which result in a lower cost of power. In addition, wind turbine generators have a longer track record in the field, which translates into a better understanding of lifetime operating costs for wind energy projects.
In order to make a real impact on the generation mix, significant deployment of renewable energy is necessary. Currently, there are 42,400 megawatts of installed wind energy capacity, and approximately 3,100 of solar in the U.S. The unit generation potential of commercialized equipment allows for a greater scale of development with wind energy technologies—each wind turbine generator can provide 2.5+ megawatts (2,500,000 watts) of capacity, whereas each solar panel provides approximately 275 watts. This point about the relative scale of capacity becomes increasingly compelling when taking land use policy into account.
Although many renewable energy projects are constructed in far-outlying, uninhabited areas, the nature of integration, transmission, and distribution costs suggests that smaller distributed generation projects located closer to concentrated demand areas are preferable replica watches uk. Land use, therefore, is an important consideration, particularly in places where the land for energy projects could otherwise be used for productive agricultural purposes. The typical footprint of a utility-scale wind turbine generator is around one-quarter acre, whereas an equal amount of generation capacity from photovoltaic panels would have a footprint of approximately 1.75 acres. In other words, PV solar energy projects are currently 7 times more land intensive from a ground cover perspective than wind farms.
Policies all over the country target solar-specific energy development. These ‘one-size-fits-all strategies’, which do not consider meaningful geographic differences, simply do not make sense. Siting solar projects where there are low insulation levels is tantamount to developing a wind park surrounded by a 15 story wind-blocking wall. In summary, while solar energy is a critical part of the solution, the continued deployment of wind energy generation with scalable, proven technologies should not be discounted.