Residential solar powered systems are clean and environmentally-friendly; but what about their cost-effectiveness or their dependence on sunlight conditions?
Here we list the possible pros and cons of 1) solar water heaters, 2) solar electricity (photovoltaic), 3) passive solar and 4) solar air space heating.
The Pros and Cons of Solar Water Heaters
The cost-effectiveness of solar water heaters (SWH) depends on market and climate conditions.
- The solar water heating technology is clean and environmentally-friendly;
- Solar water heaters are tested, reliable, free-maintenance and have a long lifespan (25-30+ years) and...
- They can be cheap and cost-competitive in hot and mild climates.
- SWH effectiveness depends largely on solar resouces;
- SWH require back-up (gas) systems;
- SWH require anti-freezing features in cold climates, and regular maintenance.
The Pros and Cons of PV solar systems
The prices of solar PV modules have decreased considerably over the last years, but prices also depend largely on the cost of the inverter, wiring, site arrangements or on "business processes", that is, costs of financing, permitting and inspections; and depend also on issues such as mass installation and standardization.
If you live in a cold climate, it's important to reduce your electricity bills to less than, say, 5.000-6.000 kWh/year through energy improvements (see Before Installing Solar Photovoltaic). Only then you should invest on a PV system, able to meet most of your electrical needs.
- Solar PV systems are a clean and environmentally-friendly technology.
- They can operate for 25+ years without significant maintenance and without operating costs.
- Price: in the US, a typical 3-4 kW system, may cost you $20.000 or more
- Paybacks can be long.
- PV effectiveness depends on solar resources;
- Back-up systems (for off-grid PV systems) are expensive.
The pros and cons of Solar Space Heating
Most solar space heating systems rely on a solar air panel installed on an exterior wall or roof; the panel is designed to warm the air coming from a room or part of the house, which is then pumped into the house. The idea is simple but the results rather mixed; they depend largely on design and climate issues and on insulation levels.
Solar space heating with solar air panels is cheap and appealing.
Mix results: not reliable or efficient without proper residential design features or high levels of insulation.
Not a ready-to-use solution.