3 Common Criticisms of Solar Power, Debunked

14th Aug 18

Written by James Doyle

Emerging technologies must normally overcome skepticism and opposition, and solar power has not been exempt from this. The existing arguments against photovoltaic technology criticise its financial viability, technical aspects, and even its environmental impact.

This article will focus on debunking some common criticisms of solar power – the ones that seem the most convincing. There are many weak and speculative arguments that can be easily dismissed, such as claims that solar panels kill plants by absorbing sunshine.

Criticism 1: Solar Power In Unreliable Because It Needs Sunshine

Solar photovoltaic systems are often criticised because they cannot deliver electricity at night, reaching full output only for a few hours around noon. This argument would apply if the plan was to make solar power the only electricity source, but any power network operator can tell you that a mix of energy resources is preferred over a single generation method. Wind turbines faces a similar argument, due to their dependence on the wind.

Actually, all electricity sources become less reliable if they are used alone, not only solar power. Consider the following examples:

  • Coal-fired power plants are inflexible – their output cannot be ramped up and down according to changes in consumption. A 100% coal-fired grid would be unable to respond to demand peaks, like the one that happens after sunset when the population is returning home, and turning on the lights and other appliances.
  • Hydroelectric power plants offer low-cost electricity and a fast response to changes in demand. However, a region relying exclusively on hydroelectricity is vulnerable to blackouts during a drought.
  • Natural gas turbines are also highly responsive, but they depend on a fuel that suffers from volatile pricing. Natural gas is also more difficult to handle than liquid fuels, and a fault such as a leak in a key facility can compromise the gas supply for power plants.

When left alone, all electricity sources have limitations, but a power network with a mix of resources is much more resilient. In Australia, blackouts are normally blamed on the large number of commercial solar systems in rooftops – actually, most blackouts are caused by network issues and by faults at coal power stations.

This argument also ignores energy storage, which is expected to become much more affordable in the short term. When intermittent generation systems such as solar arrays and wind turbines are complemented with batteries, they stop being variable because stored energy covers their gaps in production.

Another version of the unreliability argument claims that rooftop solar systems cannot tolerate power grid disturbances, getting disconnected with even minor fluctuations of voltage and frequency. Actually, the opposite is true: the inverters that manage the output of solar arrays tolerate fluctuations, and conventional power plants are more likely to disconnect first.

Criticism 2 – Solar Power Has Made Electricity More Expensive

This argument was true in the past century, when solar power systems were over 10 times more expensive. However, solar farms are now achieving some of the lowest generation costs in the world, along with wind turbines. For example, in a power auction held in late 2017 in Colorado (USA), wind and solar power could beat the electricity cost of existing coal power plants.

In Australia, wind turbines and solar systems are often blamed for the high electricity tariffs, but there are many scientific studies that debunk this. Electricity in Australia is expensive due to network costs and retailer margins, which normally account for more than half the power bill you pay. Electricity generation is actually cheap, and renewable energy subsidies only account for a minor portion of the power bill.

Homeowners and businesses who sign a solar Power Purchase Agreement (PPA) get electricity prices up to 50% lower than their normal tariff, and large-scale solar farms can now easily beat the generation cost of coal power stations. At all project scales, solar photovoltaic systems are delivering electricity for a lower cost that the alternatives.

Criticism 3 – Solar Power Has An Environmental Impact

This is another argument that is partially true: there is an environmental footprint from manufacturing the components of a solar systems and shipping them to project sites. The construction process also has an impact, and utility-scale solar farms use large areas of land.

However, this argument fails comparatively, since all power generation systems have an environmental impact due to manufacturing and construction. The difference is that solar systems produce no emissions during operation, while coal power stations normally release over 1 kg of carbon dioxide per kilowatt-hour. Natural gas can be misleading because it has the word “natural” in its name, but it releases around 500 g of CO2 per kWh.

The environmental impact of a new solar array is normally offset in less than 4 years, which is great considering that solar panels last over two decades. On the other hand, coal and gas-fired power stations have an ongoing environmental impact. The argument that solar power must be avoided due to its environmental impact does not apply, since the long-term environmental benefit is many times higher than the initial impact.

  • Assume you have a 5-kW solar array at home, producing 7,000 kWh per year.
  • If this electricity was previously provided by a nearby coal power plant, your environmental footprint is decreased by 7,000 kg of CO2 per year.
  • After 20 years, your solar system will have kept 140,000 kg of CO2 away from the atmosphere.

This simplified example is for a small residential-scale system, and the environmental benefit is significant. As the scale of the project becomes larger, the avoided emissions increase proportionally.

Conclusion

Solar power has become one of the cheapest electricity sources in the modern world, beating even the price of coal generation in many cases. Although photovoltaic system are daytime power sources, this will change as the cost of batteries decreases.

In addition to lowering electricity costs, commercial solar systems reduce the environmental footprint of homes and businesses – the initial impact of manufacturing and installation is minimal compared with the benefit of avoiding carbon emissions.

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