Energy harvesting
Power sources
Wind
Thermoelectric
- Peltier
- Thermoelectric generators (stoves)
Piezoelectric
- Mide V21bl is $65
- Should also work by shouting into a speaker or microphone, or a raw piezo transducer.
Electric field
LTC3588 datasheet suggests two 24"x36" copper panels around a fluorescent lighting fixture.
Solar
Biological
http://www.bbc.co.uk/news/technology-15305579 http://www.ncbi.nlm.nih.gov/pubmed/22816654
Power storage
Supercapacitors
Supercaps are capacitors larger than about 1F. A modern 400F supercap costs $20. They are expensive, but have the advantage that they are designed for many recharge cycles. A fully charged modern 400 F 2.7 V supercap (with 3.2 mΩ DC ESR) contains 1458 J or 405 mWh of energy.
Gravity
When you have power, pump the water up to a water barrel mounted up high. When power is low, have it flow through a hydro generator such as this one or this one.
Integrated circuits
LTC3105
Guan has an LTC3105 breakout board. LTC3105 is an energy harvesting circuit that combines three functions:
- A step-up (boost) converter that can operate from very low input voltages
- An LDO regulator
- Maximum Power Point Control (MPPC) to ensure that the circuit does not load the input below a set voltage
This photo shows an LTC3105 breakout board powered by a bench power supply at 0.5V. The output is set to 5V and the LDO, unconnected here, at 3.3V. The board is powering an LED at about 20 mA. The power supply is supplying 430mA, so the efficiency is about 45%.
LTC3588
LTC3588-1 has a full wave bridge rectifier built in and can operate from 2.7V to 20V. It is suitable for piezoelectric and "full size" (multiple series cell) solar panels.
LTC3108
LTC3108 can be combined with a 1:100 stepup transformer to operate from inputs of 20mV. It is suitable for low voltage thermoelectric generators such as Peltiers heated from human skin.
bq25504
bq25504 is a boost converter that can operate from 80mV (startup voltage 330mV).
