Monday, November 16, 2015

We hear solar energy mentioned when climate change is discussed. How do we know how how solar fits into this?

Solar energy, itself, does not release greenhouse gases (although the energy required to make solar panels, themselves, often does--the precise "cleanness" depends on the specific technology, but modern technologies are cleaner than the status quo). At the same time, they absorb energy and pump it other places in the form of electricity (and, ideally, don't reflect much back to space). Consequently, solar panels change the energy distribution in their immediate vicinity. Computer models are used to predict the effects of solar cells on their local environment. Aixue He et al. recently published a paper discussing these effects. This paper was then picked up by the Washington Post. Solar panels, themselves, lower temperatures in their immediate vicinity. They absorb energy from their surrounding and convert it to electricity, which is sent into cities and towns. Those areas, then, use the electricity, often in ways that release more heat, resulting in warming of urban areas. It is important to note that these temperature increases are much less than those predicted without the use of solar or other clean energy sources.

It is important to note that precipitation is also affected by air temperature. Cold air can't hold as much moisture. If deserts are colder, they are often drier. Solar panels, where they are set up, decrease the local temperature, which A. He et al.'s study suggests would slightly reduce cloudiness and precipitation. It only takes a 2 C temperature decrease to reduce precipitation by 20 % in desert regions. For these reasons, it was found that placing solar panels in a mixture of urban and desert regions minimizes many of the local environmental impacts of solar cells.

The moral of the story is that no matter what you do, the environment is effected. It is just a question of degrees and in what way things are affected. 

Friday, November 13, 2015

What is graduate school like? How is it different from other schooling?

Graduate school is like no other beast. In the sciences, you both do research and take classes. When you start out, you are mostly taking classes but, as you progress, you do more and more research with fewer to no classes. By the time you graduate, there is little difference between being a graduate student and being a postdoc or research scientist. It is a transition and learning period. By the end, you are the world expert on the topic of your research. Answers are not in the back of a textbook or online. You make your own questions.

Wednesday, November 11, 2015

What does it mean that solar energy is growing? What are all these costs being thrown around?

According to the Motley Fool, 40 % of all new electricity generating capacity during the first half of 2015 came from solar energy. Yes, it still accounts for only 0.4 % of total electricity generation in the US, but this just demonstrates how much built up generation capacity that we have. While solar modules are being installed at a fast rate, the energy needed is also growing and building a power plant is a long-term commitment. It takes time to gain market share.

There are a lot of different metrics involved in calculating the cost of solar energy. One must account for the basic cost of a module, the installation costs, and the cost of electronics used to interface the module with the grid. For some applications, energy storage batteries must also be taken into account. Many reports of cost do not take all of these costs into account. Several years ago, people were really excited about module costs lowering below $1/Watt. As you can see, module costs are now well-below that price. Also, there is a price difference between industrial-scale and roof top (residential and non-residential) solar energy. Industrial scale production is less expensive than roof top energy. These costs also vary by location. It will cost more to install a solar panel in areas where installers lack experience.

Source: Deutsche Bank, Vishal Shah, for rooftop market
Therefore, when you hear people talking about solar and citing costs, always ask what they are referring to.