Hi, I would like to know if adding solar panels with powerwalls a tax right off on a rental?

Yes - may potentially be eligible for bonus depreciation.Not eligible for tax credits if it is 100% rental.

One question that might not matter, who pays the electric bill? If tenant, do you charge more rent for this feature. I would say if it improves your property or saves you money on your electric bill then yes. Your CPA would be better to advise you on this.

There is a 26% tax credit when solar panels are installed this year, but that credit goes down to 22% next year, and goes away completely after that unless legislation changes soon. I am a residential solar panel consultant and my company partnered with a CPA firm. In most cases, we are able to get the 26% tax credit, and also above the line deductions that equate to around 35-40% of the entire system cost. I am happy to answer questions if needed.

all legitimate expenses are "write offs" because they get deducted from your income. capital expenditures / improvements are a bit of different story with a depreciation schedule attached.