The Disadvantages of Solar Energy
With the recent demand of Solarize Philly, it’s no secret that solar is hot in Philly. We’re always told that Solar power holds a lot of promise….but. There’s always a but – some reason why solar won’t work. What are the disadvantages of solar energy, and how can we get around them?
The future, we’re told, will run on the sun. Gone will be the days of polluting fossil fuels, of powering everything from our cars to our blenders to steel mills on the squished remains of prehistoric plants and animals. Our future is one where we will pull our power from that burning ball of hydrogen in the sky.
Solar power – harnessing the power of the sun for our cars, blenders, and steel mills – sounds far-fetched, even in today’s world.
Commonly debated Disadvantages of Solar Energy
Cost of Solar Energy
A widely talked about disadvantage of solar energy is that it is more expensive than traditional sources of energy. Although this was once true – and still is true in many places – it is not true of solar energy in general. As technology has improved over the past several years, solar has become very cheap. Solar power has even undersold fossil fuel-derived power in places like India and The United Arab Emirates. Just this past October, an Abu Dhabi-based company submitted a bid to build a solar plant in Saudi Arabia – and claimed that could produce energy for under 2 cents a Kilowatt-hour. In comparison, Philadelphia residents paid 15.8 cents a Kilowatt-hour for energy this past July – 8 times as much.
Supply Chain Issues
Another commonly misunderstood disadvantage of solar energy is that solar panels have a supply chain full of toxic chemicals and environmental damage. A Photovoltaic (PV) panel (the type you see on rooftops) could be manufactured by any of several dozen companies, using a handful of different technologies.
Some of these companies and technologies have a more significant impact than others; for example, some types of PV make heavy use of cadmium (a carcinogen), and some companies have been known to dump their waste into local rivers. Several organizations track the companies with the best and worst practices: for example, the Silicon Valley Toxics Association scores the largest manufactures on a yearly basis. PV panels are also almost entirely recyclable, although large-scale recycling facilities do not yet exist.
However, it is important to remember that PV panels are not the only source of solar energy. Solar thermal plants use the sun’s heat to produce steam, which in turn drives generator to generate electricity. This process relies on technology that has been used for nearly a century and sidesteps all the supply chain concerns surrounding PV. Passive solar heating and cooling – creating buildings that use the sun’s rays to heat or cool their interior – use solar energy to provide a service that would otherwise be produced by electricity or fossil fuels. Both of these technologies have to be considered alongside PV panels when assessing the overall impact of solar energy.
What about rainy days? Solar Energy Won’t Work!
Perhaps the most well-understood disadvantage of solar energy is that it depends on the sun – which doesn’t always shine. This is an inherent disadvantage of solar power, but it doesn’t mean that solar isn’t feasible. There are two fundamental ways around this limitation: storing energy generated when the sun is shining for use when it isn’t, and transmitting energy from sunny places to not-so-sunny places.
For those who see solar power as a way to ‘get off the grid,’ storing excess solar power is a must. Large-scale solar producers (such as utilities or large private institutions) often use pumped hydro energy storage to store energy. Using this simple technology, any energy produced by solar but not immediately used is put to work pumping water uphill, or into a water tower. Then, when the sun stops shining at night, that water is released through a turbine that generates electricity in the same way a hydroelectric dam does.
For small-scale solar users who don’t want to install a water tower in their home, batteries have become dominant and inexpensive enough that you could power your house off one. Tesla’s ‘Powerwall’ battery is the first accessible battery of this type, and when combined with rooftop solar it promises to keep a standard home off the grid for at least a week at a time.
How to Spread Solar Energy Across the Grid
The other way to get electricity without sunshine is to import it from places where the sun is shining. We ship energy across the grid all the time – the electricity you use in your blender may have been created hundreds of miles away, in any one of the power generating stations plugged into the Northeast power grid. It might have even been produced by a solar plant. But the problem with the electricity grid – our best way of transmitting power – is that it’s designed to only works in one direction. Large energy producers pump electricity into it, and consumers pull electricity out of it. This necessitates that solar generation is done at large, centralized power facilities, which means that a whole solar field could be crippled by a single cloud.
It’s not always sunny in Philadelphia, but it is always sunny somewhere. In theory, spreading solar panels across a large area (like on everyone’s rooftops) would make it likely that at least some of them are producing energy – this is called ‘distributed generation.’ Yet until we upgrade our electric grid, we won’t be able to take advantage of this strategy. There is a lot of talk about creating a ‘smart grid’ that can handle two-way power transmission, store excess energy, and better inform electricity consumers; but re-making the grid is a complicated challenge that municipalities and utility companies aren’t always willing to take on. And this fact may well be one of the most significant disadvantages of solar energy.
However, progress has been made. 38 states (including Pennsylvania) have mandatory Net Metering rules, which means those who produce their own power via solar can sell their unused electricity back into the grid. Rooftop solar continues to get cheaper and more convenient as technology improves, and municipalities across the country have been lending their support to solar projects. The solar industry has an inertia that is likely to carry it over any obstacles it comes across.
There are still disadvantages to solar energy, but these are quickly being overcome. As far-fetched as it sometimes sounds, there’s every reason to believe that our future will be run on the power of the sun.
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