Getting a new greenhouse? Now what about lighting?

A new 6x8 foot greenhouse is arriving on Tuesday. I bought one that sacrificed some translucency for better insulation. At this time of the year the sun is weak anyway, so I have to put in some lighting. Because of where the sun is in my yard, power is a problem. I did find a 72 watt solar farm that was reasonably priced.

I'm trying to keep the cost down at this point. And the power consumption. I thought of LED lights, but they're expensive.

I plan on having three shelves running along both sides of the greenhouse. That gives me 32 running feet of shelving for seedlings. I'm concerned about putting fluorescent lights the recommended 4-6 inches above each shelf because of water dripping from above. I thought of wrapping Christmas lights around the shelving posts, but I've been reading they don't give off much light? I'm talking about older style bulbs, not LEDs.

Does anyone have any suggestions?

LED bulbs will pay for themselves by saving on the power consumption, so take another really good look into these.

Make absolutely sure the fixtures are OK for outdoor use. These will be OK in the rain, so should be OK in a greenhouse.
Do all the connections with water proof connectors, not regular electrical wire nuts.

Look into set ups that are specific to plant growth. Look for the PAR rating of each bulb. Plants use certain of the red spectrum and certain of the blue spectrum, but so little of the others that a bulb for plants looks sort of dim to our eyes.
Xmas lights are pretty much worthless unless you can find out exactly what color wavelengths they put out. There are no reflectors on them, either, so even if they do produce the right light it is going all over the place, only a small fraction landing on the plants.
In an LED fixture there will be a mix of red, blue and white bulbs. The white ones make it look better to us, but also supply the other wavelengths that plants do use, but in small amounts.

Another way to go is fluorescent T-8 or T-5 bulbs.
Getting a great reflector is the key here. There is a 4' fixture with a reflector that looks like diamond plate, and is shiny steel looking, uses T-8 bulbs. The reflective qualities of this are so good it is worth the extra money. I have seen these at Home Depot. You still need to get the right T-8 bulbs. 'Daylight' is pretty good, or see if you can find some 'plant and aquarium' bulbs in that size. You probably can.

About budgeting:
If you spend $100 but only 1/4 of the light you buy (both fixture and paying for electricity) is actually benefiting the plants it is the same as spending $400 and doing it right.
I wish there was a cheaper way to do this sort of thing. LED fixtures and bulbs are coming down in price, and increasing availability.
Aquariums have the same issues. People who enjoy planted fresh water tanks are always looking for the most efficient lighting.

Another thought:
If you want to stagger the planting over a month or so you might be OK getting away with fewer lights. By the time the later plants are in need of the light the ones you planted earlier might be ready to harden off.

You aren't going to make much of an impact outside. Even on a cloudy day it's still much brighter outside and turning on a light doesn't make much difference.