A friend likes to say, "No rational angel will invest in your company. No rational angel would invest in any company. The only angels that invest are irrational." This is his way of asking what else the angels are searching for when they make an investment.
I'll phrased it as, "The benefits an angel is looking for when he invests is always more than just monetary."
RT http://twitter.com/vcbasics">vcbasics: Solar thermal works best with an electric grid. Photovoltaic is the best solution for onsite generation and onsite usage