Our Technology Future - Energy, Part Two

Continuing the discussion from yesterday, we’ve established the fact that nuclear energy is powerful. However, the current tech for it is highly controversial, and not terribly clean. And the potential for the “better” nuclear technology is still a matter of practical engineering challenge.

That does leave a few other possibilities.

There is solar energy. The ever popular alternative for decades, solar energy is the natural extension of the nuclear option. That is because the basic energy source is the same thing – the energy released by the incredible power of nuclear fusion and fission. So if solar panels are supposed to function as an extension of the same kind of energy, then why not use that? Why bother with building our own tiny sun?

The problem is in harnessing and storing that power.

Solar panels are not terribly efficient in terms of harnessing all of the energy there is in a single ray of sunlight. Sunlight contains energy in its varied spectrums (infrared, ultraviolet, etc). Solar panels – precisely their photovoltaic cells – cannot harness all of that energy in those various spectrums at once. The cells have to be designed to work with one spectrum or another; only the infrared or only the ultraviolet.

At current, the most efficient solar panel technology only converts about 20% of the sunlight it contacts with into useable energy. Proposed changes to solar technology would effectively place a prism over the panels, breaking up the sunlight into its varied wavelengths and directing the individual wavelengths to a photovoltaic cell that is designed to capture that type of energy. This would boost the gains to around 50% - not too bad, but still not “perfect”.

One of the bigger problems with solar is retention and transmission. Imagine placing a large field of solar panels, even at their current energy production levels, someplace above the Arctic Circle during the summer, when the sun never sets. For a good chunk of the year you would have solar panels constantly feeding on sunlight. The problem is storing that energy and then distributing it to the places that need energy. In short, our battery technology can only store so much of that energy much less reliably or effectively transmit it across the existing power infrastructure.

Moving down the line from solar you arrive at wind. I like to bundle this with tidal force generation since it is a very similar concept. A catchall term would perhaps be Turbulent Fluid Power Generation (scientifically speaking air is fluid). Wind turbines look to use the wind turning the blades of a large fan spinning a generator. Tidal generators use underwater currents to do the same thing.

The underwater ones are much more efficient in that if placed in the right spot there will almost always be a strong enough current to turn the turbine and generate power. The most efficient water turbines can achieve more than 90% efficiency. Bad news is that those types of currents are generally located too far off coast and too deep to access. So we build dams. But dams themselves create other environmental issues; from the obvious of disrupting natural ecological patterns, to the less immediately visible problem of desertification (the process by which areas become arid and turns into a desert). The turbines themselves, however, tend to not present many problems at all and are one of the truly clean energy sources out there.

The wind turbines tend to be about as clean an energy source as you can get. The problem is that few places have the constant presence of winds to spin a wind turbine. Furthermore many designs fail to capture significant amounts of the available wind, and further there is the energy loss of the friction of the blades turning, among other things, resulting in a mere 15% of the theoretical energy generated by the wind actually being captured and converted into electrical power. This is achieved by making them at a very large scale and placing them in very open areas, like off the coast at sea. But many people dislike the aesthetics, and some more recent reports allege that the blades of these giant fans have been killing birds, including some endangered species of eagles.

Moving further down the line you get hydrogen fuel. The problems with this are numerous. Hydrogen doesn’t occur by itself naturally. It is usually connected to something else (like with oxygen to make water). To use hydrogen as a fuel means that you have to split it off from its companion element, separate it from water to get just hydrogen and oxygen. We can do this, but the process itself requires energy, meaning you need another fuel source generating power to create the very fuel you need to generate power in the first place. If you expand it enough, you could create hydrogen fuel, use it to generate and store energy, and then use that energy to further create fuel.

All told, hydrogen fuel while in theory also very clean – even producing clean, fresh, water – is very volatile. The energy generation is created by recombining the hydrogen and oxygen to make water – basically a nuclear fusion reaction with non-radioactive elements. If this isn’t done carefully you can get massive explosions with temperatures over 3600° Fahrenheit. What’s more, even wind turbines, with their noted lack of efficiency, turn out to be an all around better energy source – cleaner, safer, and able to generate more useable energy. The benefit of hydrogen fuel over any of the other energy alternatives so far, however, is that it can be used in a smaller form-factor, namely cars. 

There's one more viable alternative... that I will discuss tomorrow, as well as naming my idea of the best policy forward when it comes to energy technology.