Long term, Space Solar Power (SSP) can supply massive amounts of electrical power to Earth with no greenhouse gas emissions and no dependence on foreign energy sources. The basic idea: gather solar energy in space and transmit it to Earth. Today's satellites already use solar energy and transmission has been demonstrated with 90%+ efficiency. If the space segment is built from lunar materials, SSP may be the cleanest possible energy option since most of the work is done in space. The energy available is far, far more than used today, more than enough for everyone.
However, SSP will be very hard to develop. The engineering problems are staggering and the economic problems perhaps even more difficult. While there is no market risk (the total energy market is measured in trillions of dollars), to be successful SSP must deliver energy at a price comparable to the alternatives. This, some have argued [Fetter 2004], is impossible as space is a difficult place to work and on Earth things are much cheaper. Others have argued that supplying the enormous market for energy can give SSP the economies of scale necessary to drive prices down to competitive levels [Globus 2009] and that the problems Fetter cites are really just R&D challenges that can be met.
While a mature SSP economy supplying terawatts of power to Earth may be economically competitive, how do we get there? The Japanese have one answer: a $21 billion program over 30 years to design and build a one gigawatt solar power satellite [Schwartz 2009]. This is roughly the necessary level of funding and time horizon for SSP development. If successful and unanswered, this project would put Japan in position to control the energy supplies of the future. Should no one else step up to SSP development and the project fails, then we will not garner the benefits of large quantities of very clean, very reliable electricity.
Let us suppose that America decides that SSP is sufficiently promising to match the Japanese effort. We could, of course, launch a similar project using NASA and America's unmatched aerospace prowess. However, the project could spend the entire $21 billion and fail to build a satellite or it could have massive cost overruns -- not uncommon with large aerospace projects; and even if successful only a single satellite would be built with no mechanism to insure that power would be produced economically.
Fortunately, there is another way that might work better: prizes. The prize system I will describe will deliver at least one working powersat for each billion dollars spent. Should no one build a working powersat, then the money won't be spent. It is far less risky than a traditional $21 billion aerospace program and could deliver much greater benefits. Here's how it might work:
Congress places $21 billion dollars in escrow (either all at once or over time; say $1 billion a year for 21 years). The prize is spread out over 21 levels, one billion dollars each. The first level pays $5/kw-hr (a kw-hr is one kilowatt -- one thousand watts -- enough for ten 100 watt light bulbs for one hour) delivered to the ground, the second level pays out $4/kw-hr delivered, and so on according to this table:
|level||price ($/kw-hr)||total kw/h purchased||sat size (MW)||days to earn entire prize|
The first column is the level, which is also equal to the number of billions available. The second is the amount paid for each kw/hr produced at that level. The third column indicates the number of kw/hr that will be purchased if the whole level is claimed. The fourth and fifth column are linked. The fifth column is the minimum number of days necessary to earn all of the prize money with a satellite that can deliver the amount of energy indicated in the fourth column; which gives an idea of the time it will take to collect the whole $1 billion at each level once a satellite starts producing power. Note that the final level, three cents per kw-hr, is about the price of the cheapest electricity produced in the U.S.
The decreasing price forces suppliers to develop better and better technology to continue receiving prize money. Of course these levels and the total cost is somewhat arbitrary, other levels and totals might work just as well or better.
The rules of the contest are as follows:
Once a satellite has won all the prize money possible, the owners are free to sell power to whomever they please.
Interest earned by the money in escrow can be used to fund pre-competitive research at universities and laboratories into SSP-related technology or simply returned to the treasury.
Any funds not claimed within 40 years of the start of the program will be returned to the treasury. Thus, we either get working SSP systems that deliver power to Earth or our money back, guaranteed. A prize of this magnitude will very likely generate a large number of competitors. Most will fail, but that does not matter. If a few succeed we will begin to tap an extremely clean, nearly inexhaustible, very safe supply of electrical power that will last for billions of years.
I don't know about you, but this seems a much better use of a billion dollars a year than almost, although not quite, anything else I can think of. We either get our money back or massive quantities of emission free, domestically produced, clean power and a major space industry with huge growth potential.