Hopefully the time frame is closer to 6 months, I don't want to renew my apartment lease.  

Knowing that, if I did buy the property, I may slightly increase rents at renewal time.

Changing to your lease probably won't change anything.Personally, I would notify them - in writing - that I intend to "renovate" the unit when their lease expires and that I will not be renewing.

Going into 2018 still ranks #2.https://solarpowerrocks.com/2018-state-solar-power-rankings/Factors include:1) Overall Grade 2) Renewable Portfolio Standard 3) Solar Carve Out 4) Electricity Price 5) Net Metering 6) Interconnection 7) Solar Rebates 8) State Solar Tax Credits 9) Performance Payments 10) Sales Tax Exemption 11) Property Tax Exemption--It's not all just about sun hours.. tax incentives, rebates, and local policies make just as much of an effect on solar viability. 

Re laundry money, i never include this in my calculation - i simply look at it as bonus income. your vacancy at 3% sounds low, again not knowing the location its hard to sell. 5% would be my lower estimate in high demand location and proven 100% occupancy in the last 2-3 years.Repairs and maintenance, unless the property was recently renovated top to bottom or you would renew the large items like roofs, HVAC, water heaters etc 5% and 4$ is tight. 

You might make a reasonable argument, if you were going to issue currency based on standard, that that standard should be a resource that can be depleted and/or renewed, such that the circulation of fiat at any time was dependent upon the health of that resource. 

He has been with a large franchise for several years but due to high fees is not renewing with them this year.

As far as expenses, I budget 8.3% for vacancy so that I have a month reserve by the end of the lease, then lower it if the tenant renews for another year.

Everything I read is that there’s supply concerns and OPEC may not renew their deal of lowering production. 

How do extension/renewals work?