HYSR is a great one but the one thing is we don't know if their development will succeed. There is a higher risk but higher potential of gain. On the other hand SLTD is about to become profitable company and finishing up the third generation prototype which is the last one before commercialization meaning starting production of their new 26% highly efficient solar panels. If I were you I would put all the money into SLTD then sell some when the price goes up and buy HYSR because their technology would probably take another 6 months to be ready for production.
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