How solar power can reduce the planet's emissions

Pollution is one of the world’s big killers. In order to combat climate change, we need to rapidly move from fossil fuel energy to clean, renewable energy. The two energy sources most responsible for decreasing global warming wind and solar power.  However, there are other sources that have great potential.

How much change can we expect from solar?

Uneducated people doubt how much wind and solar can supply to a country’s electricity grid. This is a particularly challenging question to answer in part because both solar power and wind power fluctuate in both space and time. We all know solar panels work well during the day when the sun shines – they don’t work so well at night. And wind turbines only send electrons when the wind is blowing. Batteries that store solar energy are becoming cheaper and more readily available. Fortunately, these two sources of energy fluctuate in ways that complement each other. For example, solar power generation is highest in the summer and lowest in the winter. Wind power is greatest in the spring and fall. Wind turbines work at night when solar panels are dormant. So, can these complementing variations help balance out the power that the two technologies can provide? 

Analyzing the weather data

This question was addressed in a very recent paper published in the journal Energy and Environmental Science. The author list included Dr. Ken Caldeira, who is well known for his years of work in environmental science and energy. The authors analyzed 36 years of hourly weather data (1980–2015) in the US. They calculated the available wind and solar power over this time period and also included the electrical demand in the US and its variation throughout the year. Using this information, the researchers considered two scenarios. In scenario one, they imagined wind and solar installations that would be sufficient to supply 100% of the US electrical needs. In the second scenario, the installations would be over-designed; capable of providing 150% of the total U.S. electrical need. But the authors recognize that just because a solar panel or a wind turbine can provide all our energy, it doesn’t mean that will happen in reality. 

Solar and wind power

The authors then considered different mixes of power, from all solar to all wind. They also included the effect of aggregation area, that is, what sized regions are used to generate power. Is your power coming from wind and solar in your neighborhood, your city, your state or your region? The authors found that with 100% power capacity and no mechanism to store energy, a wind-heavy portfolio is best (about 75% wind, 25% solar) and using large aggregate regions is optimal. It is possible to supply about 75-80% of US electrical needs. If the system were designed with excess capacity (the 150% case), the US could meet about 90% of its needs with wind and solar power.
Sometimes these systems generate too much power to be used. In that case, you could store the energy for later use. Imagine a solar panel generating excess energy during the day and able to store that power for night use. Power can be stored in several ways, for example in batteries or by pumping water into elevated tanks and then letting the waterfall at night and turn a turbine. 

Solar and wind can power this country

The authors modified their study to allow up to 12 hours of US energy storage. Thus they then found that the 100% capacity system fared even better (about 90% of the country’s energy) and the optimal balance was now more solar (approximately 70% solar and 30% wind). For the over-capacity system, the authors found that virtually all the country’s power needs could be met with wind, solar, and storage. This study considered only wind and solar. If other sources, such as hydroelectricity, biofuels, or even nuclear power were added, it would be relatively straightforward to reach 100% clean energy. Fortunately, people are learning to use energy more wisely, either by using more efficient products or purchasing electricity during off-peak hours. These behavioral changes can also help us reach a 100% clean energy target. The main point is the use of clean energy to power an entire country (or a group of countries) is achievable.

Now is the time to go solar

If you want to move into the future and join the solar revolution, or if you want to find out what solar panels are right for you, go to HahaSmart.com and try our price checker tool. You can see how much a system will cost, and how much you can save over the next 20 years. 

For more information relating to going solar, don't forget to visit our solar blog section for more handy guides and articles.