Requirements

After carefully evaluating how dark it is going to be - these are my thoughts. The amount of energy needed to generate sufficient light is beyond what the average survivor can conveniently generate. Any option that will require the use of any advanced mechanical devices is not acceptable. Let’s look at a typical car alternator. I own a Honda that was built in 1986. I replaced my alternator last summer. Assuming that every car runs on average 3 hours a day, my car was running for 11 years. 11 years x 365 days x 3 hours = 12,045 hours. If an alternator is used to generate light it has to be on for 24 hours a day which gives us 502 days = 1,375 hours. Given advances in technology we can get 2 years out of each alternator. We are there for at least 25 years of gloom. In addition the amount of light needed per plant is quite high. At least 3 - 12 V lights have to be used per plant (never mind the light spectrum at this point). You will need at least 100 healthy plants per family. Minimum.

Offered by Chris.

Its the diffused light that the plants use in the majority of their photosynthetic cycle. Plant leaves have more than three times as many somas on the undersides than on the top. Although they do absorb light on the top surface of the leaf, they utilize the light they collect on the underside far more efficiently. (Somas are gas exchange sites - the place where CO2 is taken up and O2 is released.) Think about greenhouses and how diffused the sunlight is once it passes through two panes of glass or plastic, yet greenhouse plants do so well, comparatively!

Offered by Roger.