Under the renewed guidance of an environmentally eager federal government, the race to transform the national energy grid from fossil fuels to renewable energy is picking up speed. Now, however, the debate has transformed from whether we should pursue alternative energy sources such as solar power to how we should get there.

In recent years the federal government has strongly supported utility scale solar power primarily in the form of large solar thermal plants, otherwise known as concentrated solar power (CSP). Yet the renewal and enhancement of residential solar tax credits and controversy surrounding remote desert CSP plants has heated up the debate as two which is better; large-scale solar power plants or small-scale residential solar power systems. Each has its pros and cons, revolving around a number of issues. Following are some of the major issues, and how they affect this ongoing debate:

Transmission - Proponents of residential, or distributed-generation, solar power argue that rooftop systems require few upgrades to the national electric grid, at least none that are not already necessary, while CSP plants require long and expensive transmission lines.

Sooner or Later - Proponents of CSP argue that if its renewable energy we want, the only way to get there in the time frame proposed by scientists and government is to adopt large scale power plants. Rooftop solar would just take too long. Residential solar enthusiasts argue that affordability, not simply ability, is the problem, and more aggressive policies such as feed-in tariffs (see Germany) would catalyze the residential and commercial PV industry.

Environment - A major reason for concern at the moment regarding CSP plants is their environmental impact. The reason these plants must be remote is that they require large swaths of land for acres of solar collectors, upsetting the local ecosystem. They also require large amounts of water for cooling in desert regions already short on water supply.

Cost - Perhaps affordability is the issue behind residential solar's slow spread, so why not let large solar firms and utilities pick up the slack with concentrated solar plants?

Space Saving - Some proponents have claimed that a single 100 square mile CSP plant in the desert southwest could power the entire United States. The popular counter to that is simply that there is already many times that amount of land available on rooftops throughout the country.

Energy Independence - A big plus for solar power of all types is its potential for reducing our dependency on foreign energy sources. While CSP takes big strides in that direction, it ignores the individual's energy independence. Rooftop solar has the potential to free families from utility bills altogether.

While individually described, all these issues are interrelated in their own way. Lower cost rooftop solar would facilitate that homeowner independence while naturally encouraging space and land savings by reducing the need for large-scale solar power plants. On the other hand, solar cannot get any cheaper than not having to pay for it at all (up front) and only solar power plants can effectively and speedily "clean" up the national grid while reducing costs and increasing energy security.

And the debate goes on.