We started with solar concentrators and moved to
electrical heating
methods, as the
cost of PV decreased.
The energy collection surface needs to be higher (PV has low energy
conversion efficiency) but the systems become simpler:
- Not so sensitive to solar tracking
- Works also with indirect sunshine
- No heat transfer loop, the energy transport is an electric wire
- Flexibility in the location of the heat source (heating element) in
the storage
- Can combine PV/Hydro/Wind
- Can be stand-alone or integrated with existing systems (e.g. battery
based or grid-connected system)
- Can most often be upscaled more readily
- Technically simpler than concentrators with heat transfer systems
- Can be easier to produce and maintain locally
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Stand alone PV - heat
- PV panels can power a heat storage directly.
- A load controller is needed, to give a set voltage, or to
give the maximum power point (MPPT controller).
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Excess power to heat storage
- A heat storage can be attached to a standard battery based
system. The standard battery system can also be extended with
more PV panels.
- A diversion controller is needed, as we try to avoid the
heat storage to be connected to the battery (no cooking on
battery).
- When the battery is full, the excess power goes to the heat
storage.
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Grid connected
- A heat storage can be linked to a grid-connected system,
where the grid serves as the energy storage for excess locally
produced electrical power.
- The excess energy can be utilized locally by charging a heat
storage for cooking.
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