Powering a Steam Engine with a Solar Boiler
The amount of correspondence we get concerning powering a steam engine with a solar boiler is considerable. There are some problems with the concept. These problems are probably not insurmountable, but they are considerable.
The first problem is the designer of the system. Are you an “armchair engineer,” a “Professor Pinkhands” (long on theory, short on actually building anything) or a “hands-on” type of guy? If the latter, you might turn out to be the Bill Gates of alternative energy.
The second problem is in the nature of sunlight and steam. A 9-foot in diameter solar furnace, even under optimum conditions, will turn a cup full of water into steam in about one hour. A 1 hp steam engine, the smallest we make, requires 3 to 5 gallons of water turned to steam every hour. Worse, a medium-pressure steam engine (80 to 150 psi) requires incoming steam as hot as 366 degrees F. (150 psi). The steam that leaves the exhaust port is still at 264 degrees F.
The third problem is that any medium other than water has inherent problems of its own. Naphtha, which has a much lower boiling point than water, could theoretically be used. Naphtha would also double as a lubricant. However, naphtha is a toxic chemical. It isn’t something you want to be around on a regular basis. Worse, what if it leaks? Men who live in the real world and actually have to work with machinery are well acquainted with Murphy’s Law. If there is a possibility that something can spring a leak, you can make book that it will.
If you actually build a working prototype solar boiler that is actually powering one of our steam engines, we would be very interested in further discussions and negotiations. Please do not get back to us with anything other than a working prototype. We just don’t have the time for theoretical discussions.