untappedEnergy

I’m really satisfied with the new home grid system we got the other day. Now with the new Smart Appliance base from Braun I can choose to only enable boiling when my Solar Panel has provided enough energy for a cup of tea. In the Virtual Wire panel as seen in the video I can connect the two and let the Solar Panel output control the boiling of water. The base lights up to show me when enough energy is accumulated. The statistics shows that it takes roughly four hours on overcast days. But that no problem as long as my tea now is green².
I shot this video to show how I did the connection. While in there you can see how detailed the metering panel has become. For a statistics fanatic like me, I love that stuff!

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Here is a picture of the Braun kettle as well:

The Electric Kettle On Solar Power!

I had the opportunity to install a solar panel at home this easter. The usual downside of doing that is that you need a battery or a big and costly inverter to send it to the grid. Fortunately I got enrolled in a small scale smart grid roll out with my local utility. This enables me to add any generator such as a PV panel, a wind trubine, a fuel cell, or a dynamo, directly to my electrical sockets at home. If I generate electricity the utility give credits per Wh generated that I can accumulate to consume in other devices. I haven’t tested it all yet, but it feels really good already.

Rechargeable Batteries with Solar Cells

At home I always have some batteries lying around, either rechargeable or normal ones. Usually they are empty, but I’d like them to be always fully charged. I could use a normal charger and there is a lot of solar devices that charge rechargeable batteries. I wanted it simpler; why hasn’t anyone made a battery with integrated solar cells? The idea of the “SunCat” batteries where born. The batteries should just bask in the sun like a cat and left for a while, in a sunny window, they would slowly recharge.

Prototypes
During my research for my diploma I was in touch with scientists at IFE that experimented with the production of flexible solar cells. They where kind enough to send me some samples in the right dimensions that i could use for the prototypes (full set at flickr):

I had some older NiMH rechargeable batteries that i glued the flexible Photo Voltaic (PV) cells onto. The PV cells are rated at 1.8V and the batteries are 1.5V so they match quite well.

Half glued you can see the really shiny polymer substrate backside of the PV cell. The crude written text says: 3×0,6V B: 13.411.09 Which i guess is the voltage and a batch number.

Using a conductive silver pen and some flat wires from a broken canon lens I made an ok connection to the PV cell.

This setup is infact a (quite weak) trickle charger. It is not ideal, but really convenient. A second version would have some electronics (to check when full) and capacitors to charge the batteries more efficiently, but the battery would then be smaller if it all needs to fit within a C-cell battery.

The sun did not shine today, in fact it was snowing. But I’ll sure let them hang around in my window and take some more pictures when the sun shines.