Free energy?

Hi,

-This is my first topic so I hope I won't make mistake.

I strongly agree with you, but sometime it's possible to "harvest" a small quantity of energy that can be used to produce energy. For example it is possible (and it's quite simple) to use a Peltier cell to convert heat into electricity. Some years ago I've built a very simple circuit that can power a LED with a small Peltier cell (40x40) and the heat of my body. Now I'm looking on Tesla generator that sems to be able to harvest energy field and produce a very small quantity of energy (mW) that could be use with sensor network.

I've read something about Bruce De Palma but I think it N-machine ca not work.

The REAL WAY TO "PRODUCE" ENERGY IS TO REDUCE THE WASTE OF ENERGY or TO CONVERT "USELESS" ENERGY (Heat, wind, sun, electomagnetic fields).

Hi!

Hey, new to this, but very interested in converting heat to electricity!

Can you explain the theory behind a pelcier cell? I'm having a little trouble finding anyone to explain it to me, it seems like an amazing technology though that could possibly revolutionize technology!

Thanks ahead of time 3660.contentimage_1.png

I'm not sure I can be clear. It's about the kinematic energy due at thermal energy. More is the thermal energy and more is the kinematic energy that all the electrons have. If, in a diode (the peltie cell is like a big diode), an electron has sufficent energy can "jump" the potential barrier becomes "free" and can be used.

Appropriately doping and sizing the junction you can have sufficent electrons and the potential barrier.

I hope it clear... but ask for any question!

Hi!

I'm not sure I can be clear. It's about the kinematic energy due at thermal energy. More is the thermal energy and more is the kinematic energy that all the electrons have. If, in a diode (the peltie cell is like a big diode), an electron has sufficent energy can "jump" the potential barrier becomes "free" and can be used.

Appropriately doping and sizing the junction you can have sufficent electrons and the potential barrier.

I hope it clear... but ask for any question!

Hi!

I've talked to a few of our suppliers recently and energy harvesting is a big topic for them. Linear Technology, TI and Microchip all have solutions to collect and store energy from natural phenomenom like heat, light and vibration. The circuits consist of a collector such as a solar panel, conversion and a storage battery. Sometimes the circuits have a supplemental battery.

The suppliers are claiming that these circuits can power an sensor, MCU and a Zigbee type measurement node for ten years and upwards.

But I think you may be referring to cold fusion type circuits, which many invertors claim to have made. All these claims have proved impossible to replicate under controlled conditions. It is a fascinating subject and I watched a great show on it once

Hi,

Energy harvesting is indeed interesting and well understood. Look for example to solar energy. The sun produces around 1300W/m^2 of which 1000W/m^2 reaches the ground. We are able to convert 20% of the energy to electricity with the best PV-cells available. That's 200W!. The backdraw of this is the technology behind the conversion. Traditionally you would need a solar charger and battery storage device and inverter to make use of the energy. Lot's of converters, lot's of losses, lot's of money spent. The modern way of converting the solar energy is to pump it directly (via 1 boost/inverter stage) into the grid. You need the support of your electricity company to do this. For stand-alone application solar energy is nice, could even be cheaper than connecting to the grid (if the grid is not there yet) but you have to oversize the solar panel enormous to have sufficient energy the whole year round. As the winter time is really a problem for the energy harvesting (energy output may reduce to 10% of the nominal value) the system becomes relative expensive. I would say: focus on the application and make a overall efficient system. Most energy is wasted in the application. I thing is clear: if you build a solar application you MUST consider all aspects of the system and finetune each component for optimal performance. If not, your customer is disappointed. There are a lot of those around as several solar products have very poor performance. Engineers have to be educated about the do's and don't of solar technology. If not the general public will turn there back on solar products. Or: who want a solar energy driven flashlight? :-)

Best regards, Enrico Migchels

In applications I have used solar, it's been that they are either off the grid or just require power intermittantly. Then it's usually the storage device that limits its use. One problem is that at higher latitudes, the use may be more when the nights are longer, and the weather worse, so you can end up with having to over specify the solar input side to get the required energy into the system. Solar powered lighting for the Developing World is a real application, as it reduces their reliance on such as kerosene for lighting and has obvious safety advantages.