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Types of Solar Selective Coatings

Solar selective coatings are types of paint used to cover solar collectors. The collectors capture the heat of the sun and transfer it to energy for everyday use. The paint increases the absorption of this heat, helping the collectors capture as much as 90 percent of the energy generated.

Black Chrome
- Black chrome solar selective coating is made by electrochemically cleaning copper sheets. These sheets are electroplated with nickel. The black chrome becomes electrochemically deposited over the nickel coating. Black chrome is useful for places where less sun is collected.
Black Nickel
- Black nickel, like black chrome, is also electrodeposited. The coating is plated in chloride baths. It has a high absorbency of energy and emits very little wasted heat. The black nickel selective coating is made of two layers with different grades of porousness. This allows it to work well in humid conditions.
Aluminum Oxide with Nickel
- Aluminum oxide with nickel selective coatings last a long time. They have been shown in tests of diffused light to absorb heat evenly and sustain a constant temperature. Aluminum Oxide with nickel selective coatings are made by an absorbing film comprised of nickel nano-particles, embedded in a matrix of aluminum. A spin coating process and a heat treatment creates smooth films.
Titanium-Nitride-Oxide Layer
- Titanium-nitride-oxide layer selective coatings are the latest technological advance in solar coatings. They have the highest absorption rates, the least waste of energy and are extremely durable. They are manufactured using a complicated process that is applied via steam in a vacuum. This treatment has few chemicals generated or lost. This makes for a clean way to produce solar selective coatings.

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