1.Geothermal or Ground Source Heat Pump (GHP):
A geothermal heat pump can work for heating and cooling. This system takes the energy from the ground and uses it to cool or heat your space. Generally, the coefficient of performance for a GHP is 4; meaning it is 400% efficient. The video below explains the system clearly. For more information GHPs see this source: International Ground Source Heat Pump Association.
How a GHP works:
2. PV Panel Sun Shades:
Essentially, instead of shading a window with a typical shade or overhang, use a Photovoltaic (PV) panel to do the shading. This provides a dual benefit: shade and electricity. Install PV panels where they will not be shaded to take full advantage of the sun and south-facing tilted at angle of your latitude. For example, San Francisco, CA coordinates are 37.8Ë N, and 122.4Ë W – N is for latitude and W is longitude. Thus, a PV panel on a rooftop would face south tilted at 37.8Ë.
3. PV Panels on roof:
Without the benefit of shade – placing PV’s on rooftops (where it makes sense because of space requirement and non-shaded area) is a source of electricity generation for your home.
Install High R-Value, low Solar Heat Gain Coefficient (SHGC) windows. SHGC is a number from 0 to 1 that describes heat transmitted through the window; the lower the number, the lower the heat transmitted. High R-values are necessary to insulate your home and keep the cool air from escaping! Common examples are double-pane low-e glazed windows. They are generally the most cost-effective of variety of windows that exist.
5. Innovative Windows:
SunGuard PVGU.  This is a window that has PV cells integrated into them. They have low SHGC and a great R-value. Thus, provides good insulation and low heat transmittance and generates electricity!
6. Evacuated Tube Water Heater:
Install this system is for water heating. Only downside is that it produces hot water when the sun is out - so not a lot of hot water late at night and in the morning! But it definitely reduces the hot water cost for the washing machines, dishwashers, showers, etc. during the day.
How an evacuated tube water heater works:
Try and shade the south-facing windows as much as possible with overhangs/shades. South side is where sunlight hits the most during the entire day. You want to avoid having all that sunlight enter the house.
Moving air is another way to cool a space. Install ceiling or floor fans in places that do not get a lot of airflow.