One of the panelists, Avik Roy, argued that the world isn't going to be powered by solar panels. Maher countered with something to the effect of "100 years ago, nobody thought horses would be replaced by cars". And I hate that rhetorical device (the "science will deliver us" trope) because Maher's belief in technology is almost as blind as a zealot's belief in his religion. Just because we've made incredible progress in applied sciences in the 20th century doesn't mean we can achieve the same magnitude of progress in the 21st. Especially in politically relevant fields.
Solar energy is never going to replace fossil fuels or nuclear power as a main source of power generation. Here's a breakdown of our electric grid by power source:
|Source: Energy Information Agency|
Solar and wind, which make up the vast majority of the renewable category, account for 5% of US electricity generation. It's very small. The only major category that's less than that is oil, and only because we use petroleum almost exclusively for gasoline and plastics.
You might be wondering why we can't significantly increase that amount. The answer is simple: output stability. Energy output by solar and wind are highly dependent on the weather. If it's cloudy outside, solar panels don't generate as much power. If the wind doesn't blow, the wind turbines won't spin. At night time, solar has zero output.
But electricity demands are very predictable. We have peak hours in the morning (once everybody has arrived at work) and in the late afternoon (once everybody gets back from work). In order to satisfy peak demand, the electric grid has to have more energy flowing through it. That means increasing output. With coal, gas, hydro, and nuclear, this is very simple. Shove more coal through the furnace. Pump more gas into the generator. Activate another reactor at a nuclear power complex.
You can't do that with solar or wind. Even if anthropomorphic global warming is real, we still don't have the ability to force the sun to shine stronger or make the wind blow harder. There's no way to increase output at a solar or wind plant. So if the majority of our electricity was generated by wind or solar, we'd have rolling blackouts and brownouts during peak hours. That effectively turns us into a third world country.
Now take a look at this next chart detailing natural gas prices:
See that huge drop between 2008 and 2009? Part of that was caused by the recession. But as you can see, through 2012, we're at 2002 level prices for natural gas. And we certainly aren't at that level for oil, otherwise gas would be less than 2 dollars at the pump currently (the national average is currently 3.70).
What happened was a new technology was developed for the extraction of natural gas. It's called hydraulic fracturing. It's dramatically reduced the cost of extracting natural gas and dramatically increased reserves (the amount of natural gas that can be extracted economically). It has currently made natural gas the cheapest form of electricity generation in the US (at about 4 cents per kwh delivered to the end userT), and we have enough of it to last over a century.
Currently, the environmental lobby is embroiled in a huge fight with the energy sector over hydraulic fracturing. The claims are mostly bunk, despite documentaries like Gasland trying to provoke a dramatic reaction. Natural gas is cheap, abundant, and clean burning. It will substantially reduce air pollutant emissions as more and more coal fired power plants are currently being retrofitted to use natural gas.
So now you might be saying "well what happens in a century when even that stuff runs out?" The answer is nuclear fission, and eventually, nuclear fusion. Unlike solar and wind, nuclear is a proven source of electricity. It is the cleanest, safest, and (if regulation weren't such a big deal) cheapest form of energy on the planet. We have enough nuclear fuel to power the world effectively in perpetuity.
Solar, on the other hand, is just incredibly expensive electricity. So is wind. In 2010, the government spent 6.12 billion dollars on subsidies for solar and wind. Another 6.82 billion dollars was spent on coal, natural gas, and nuclear subsidies. 6.12 billion dollars in subsidies for an energy category that only produces 5% of the country's electricity. The government spent only 11% more on subsidies for 3 sources that produce 86% of the country's electricity.
This might all seem academic if it weren't for one simple fact: the modern economy is dependent on cheap energy. Think about it. One gallon of gasoline can propel a two ton car 35 miles down a highway. Next time, just try pushing your car up against a slight 8 degree incline for 100 feet. If you're the average American, that gallon of gasoline only cost you 1/6th of an hour's work to buy. But if you were to try and push your car for 35 miles, it'd take you at least a day's labor to do so. And that's just moving your car. That's nothing to say how much effort it'd take to build a car without electricity.
There's no point in throwing our capital into a sector that isn't economically viable. Wind and solar are not the answer to the country's energy needs and never will be.