PV Gap

Jenny Said:

What are better flat solar panels or the tube type evacuated tubes?

We Answered:

It partly depends on what climate you are in. In the Pacific NorthWest (Oregon, Washington State), the evacuated tubes can work better than flat plate. But in most places, using them for domestic water heat, they are about even performance. Some installers prefer installing one over the other, and sometimes it depends on the look you are going for. Flat plate can mount flush to the roof in snowy areas, tubes cannot, they'll get covered in snow.

Here's a guy in upstate NY that is running 2 similarly sized systems side by side and charting the data live. http://cwc-das.com/logger/tabs.php?logge…

Conclusion: they both work great!

Julie Said:

Air-source heat pump: is there a catch? Comparison with ground-source?

We Answered:

Ground is more expensive and the installers in my area have had problems with the heat transfer liquid. Air source is cheaper yet noisier and less efficient.