Although the solar industry continues to grow, it still occupies only a tiny fraction of the overall energy mix. In the U.S. only 130,000 homes have solar arrays.

What’s holding it up? Some blame the high cost of the technology. Others point at the see-saw nature of tax incentives.

Personally, I blame banks. If you want to build a utility-scale solar farm today in the U.S. you might be lucky to get money at 9 percent to 11 percent, according to various sources. If novel technology like CIGS or concentrators are added into the mix, expect to pay 2 percent more. The U.S. federal government, meanwhile, is currently giving money to large banks at nearly 0 percent.

“Why do I have to pay more for money than an apartment building,” asked Tim Keating, vice president at Skyline Solar, which makes a concentrating solar system. “Why are we paying a four-percent risk premium?”

In Germany, the same solar farm might be able to obtain money (a blend of equity and debt) at 7 percent or less.

The really galling part of this situation is that solar has become perhaps the safest investment in the world.

Think of it. Project financiers loan money to developers to erect power plants from readily available components that continually drop in price. Unlike a nuclear plant, solar plants don’t take years to build. Even multi-megawatt projects only take a few months. The biggest risks are (1) getting building permits and (2) landing a power purchase agreement. But since developers don’t seek financing until after these problems are resolved, those risks vanish.

The power from these plants in turn will get sold under fixed-price, long-term contracts to utilities like PG&E, Duke Energy or Southern California Edison, companies that can often trace their history back to the 19th century.

These utilities, moreover, can’t abrogate their contracts. State regulators won’t let it happen. Sure, the developer could go bankrupt, but in that case the utility or bankruptcy trustee would merely pass the power plant to someone else. Managing the plant takes skills, but it is similar to running a car wash. Have you hosed off the panels? Is the equipment plugged in?

Are there risks? Absolutely. The sun could explode. An outbreak of Ebola could decimate the population in the service territory. Rogue lawsuits could occur after approval. But in general, we’re talking about a no-risk 9 percent return. Loaning money to someone to build a gas station/mini mart on a freeway exit looks like building a fusion reactor in comparison.

And in solar, you don’t have to worry about repo men or evictions.

“Both technology and credit risk have been proven over the past several years to be very low,” said Charles Ferer, president of Sungevity. “In fact, the residential lease industry has not, to my knowledge, experienced a single default.”

The usual explanations are somewhat vague: we don’t have enough historical data. It involves unseen risk. That’s just what they charge. Project financiers could invest in something else, etc., etc.

The real explanation, however, lies in a transformation of the U.S. economy. America has become a white collar “services” economy where the highest achieving college graduates are funneled into law, medicine, consulting and MBA programs.

It’s the final step in the immigration saga. The first generation seeks money. The second one seeks power. The third one seeks two degrees. (And the fourth sells heirloom fruit at a farmer’s market.)

Unfortunately, the problem with the services economy is that it is one of the few sectors of the economy where prices only go up, not down. Back in the late '80s, for example, the top law school graduates could command starting salaries of -- gasp -- $60,000. Now they can get $160,000 plus bonuses. Partner salaries, meanwhile, have ballooned from the low to middle six-figure range to seven figures.

The salaries for those polished McKinsey knuckleheads have ridden a similar trajectory. Banks and financial institutions have a long history of fee inflation and collusion. J.P. Morgan himself repeatedly tried to fix railroad rates in the 1880s on the justification that competition would impair capital.

Part of the rise in costs can be attributed to inflation, but the bulk of it really derives from psychology. These are respected professionals! They don’t haggle! When was the last time you did comparison shopping on a spleen transplant? $850 for a colostomy bag? No way, I’ll make my own. The only lawyers that talk price upfront usually will also ask you to put the money in the metal tray and slide it forward.

Forcing the professional classes to bargain like a cabbage merchant would be a betrayal of upward mobility. Americans may elect cardboard cutout and Bain alum Mitt Romney to be president in 2012: it's the third and final sign of the PowerPoint Apocalypse.

Project finance organizations charge exorbitant rates because, deep down, they believe they are as smart and deserving as their friends that went to Goldman Sachs or hedge funds, and those guys make outrageous amounts of money.

Luckily, there are ways out of the trap. The U.S. Senate recently passed the Clean Energy Financing Act, which would effectively provide funding for projects. Will it get passed by Congress? Probably not in the near future, but maybe in a few years.

New investment vehicles could also help. Bob McDonald, CTO at Skyline, has proposed mutual funds for solar projects. Investors would plunk money into limited partnerships or some other vehicle. Real estate managers would then invest in various projects. The returns -- let's say 6 percent -- would be steadier than the stock market.

Then there are foreign banks. Chinese financial institutions have shown a willingness to fund projects that employ Chinese wind turbines or panels. Let them open up energy savings accounts.

Another idea: states like Mississippi and South Carolina could divert some of the low-cost loans they are providing to companies like AQT Solar and Twin Creeks Technologies to build new plants to solar developers. Solar farms would create construction jobs and carry far less risk. Mississippi loans money to startups at around 4 percent.

And then, after several years of watching these efforts succeed, U.S. banks might respond.