The Peltier Effect creates a heat flux between the junction of two different types of materials. A Peltier cooler is a solid-state active heat pump that transfers heat from one side of a device to the other, with consumption of electrical energy, depending on the direction of the current.
Want to shoot the stars? PrimaLuceLab offers the D5500a Cooled ($2400 (at current exchange rates,) that’s based on Nikon’s D5500. It harnesses the power of a cooled CCD camera with the ease of use of an SLR that allows you to record stunning images of deep sky but also of the planets and the Moon! The cooling system, down to -27°C , with Peltier cell dramatically reduces noise during long exposures and the front sensor filter is modified—for astronomy—for higher sensitivity especially in the wavelengths of the red. It also includes anti-dewing system that only heats the front filter (and not the sensor!) allowing you to avoid dewing. A touchscreen display together with the cooling system control electronics is directly operated by the touch keys located on the camera, make it easy to use and 100% functional even without requiring an external computer.
The cooling system has a display that shows the current temperature of the sensor, the temperature you want to achieve, the relative speed of the cooling fan (which does not introduce vibrations) and the intensity of the anti-dewing system for the front filter. Special touch buttons allow you to adjust all the parameters to set the camera as you prefer. Temperature regulation is absolute then the sensor will work at the same temperature all night letting you record (if you want) the dark frames when you prefer!
One of the limitations of using an SLR for astrophotography is battery life. When working at low temperatures the efficiency of the rechargeable batteries drops significantly. For this reason the D5500a has a 12V port that powers the cooling and anti-dewing systems, with a 9V power output. You just connect to this socket the supplied power adapter and insert the other side in the battery compartment of the SLR. In this way, the single 12V power supply (3 amps) power up both the camera and the cooling system. Note: The D5500a Cooled requires a 12V 3A power supply not included in the package but is approx $38 (at current exchange rates.)
Canon shooter? PrimaLuce Lab also offers Canon EOS and other Nikon options.