Retirement and solar

Retirement and solar

I'm looking into getting solar. Different companies provide models based on current usage, but don't factor in retirement. Typically they expect a bit more usage after retirement, but for an EV owner with a commute, a significant amount of the charging will go away upon retirement. The projections they give are based on 25 years, and are compared to hypothetical electric bills, but if at a given point in those 25 years, usage dropped to the point that the system was consistently providing more energy than was being used, it would be overkill. The problem is I don't have any given date for retirement.

Hypothetically, if my wife decides to retire in 5 years, a system properly sized now would be overkill for the next 20 years. One sized for retirement would mean paying for excess electricity, most of which would be at night rates. But she might not decide to retire for a decade.

How do EV owners looking at solar typically factor in retirement?

Xsighted | 2 juin 2017

In retirement you need protection against sudden jumps in expenses that you cannot meet with salary increases.
Locking in your energy costs with solar is a big help.
I would not worry about overkill. You do not know what new electric costs the future may bring. Do you have a heat pump? Maybe you will drive more not less. Do you have an electric lawn mower? etc..

SUN 2 DRV | 2 juin 2017

Solar payback is usually in the 6-7 year timeframe. I'd recommend sizing your solar to payback in your expected period until retirement to breakeven by then and thus it's all upside after that.

This often means sizing the system to 70% of current consumption levels, and after retirement with your decreased commute it might cover 100%. That's a good thing for fixed income retirement budgets.

Haggy | 2 juin 2017

I figured out roughly what I use in energy for charging at home using night rates, and I decided to look at a system that accounts for my likely use after my wife and I are retired. I can then subtract that from a quote that covers current needs, divide what's left by my annual cost for charging based on the difference in what's generated, and that will give me the number of years until I'd break even on that aspect. If my wife and I are both retired in less than that number of years, it would be cheaper but it would have to come down to how much cheaper. If it's close to break even then I might as well get a system that's overkill since it would be cheaper in the long run.

My lawnmower uses little electricity. My back lawn is not very big. My front is done by the HOA. If I travel more, it will likely be with superchargers.

vp09 | 2 juin 2017

Hi Haggy,
I moved to 3 miles from my job so if I stop going there most every day, it won't have that much effect on power usage.
Wife retired last year, where she charged at work with a J1772. Now she's charging at home from our 240 volt Nema 14-50.
You bring up an interesting issue.
I've had 2 solar arrays so far. One was a 3 kW system in East Whittier installed in 2001 or so. I paid nothing for electricity for the 10 years I lived in that house. But no electric car then.
Now I am in North Whittier. I have a 5 kW system from SunPower (Solar City, our first choice, would not do it) and our last bill from SCE was minus $21.
We are running two S90Ds.
I charge two Ryobi lithium-ion batteries for my chain saw, my leaf blower (awesome!) and the trimmer (still in the box).
All after 10 pm, when electricity costs only 13c per kWh.
I'd advise you to go with the biggest solar array you can buy. We could not do that. We were limited by some California regulatory agency. Limiting us to only generating enough power to meet our expected needs.
You are not in California?

vp09 | 2 juin 2017

Haggy you mentioned "overkill" two times. Tell me what you mean by that. Do you mean that the utility would then pay you money for giving them power? Or not?

vp09 | 2 juin 2017

Sun 2 Drv I respect your amortization model giving 6 or 7 years as the "payback," but I always tell people that a solar array "pays for itself" the moment that you turn it on.

Because it increases the capital value of your property by 100% of the amount that you paid for it.


mark.willing | 3 juin 2017

Most folks don't think about these things prior to their retirement,...good to see someone with some fore thought. Unfortunately, some may have a very short retirement,...while others may enjoy an active, healthy retirement for 30+ years. During that time, prices of everyday things (food, utility rates, etc.) do not go down,...but the retirement income stays the same, or in some cases, drops. Planning for this reality by making the home as efficient as possible will be important,...prior to retirement. Solar seems like a great way to do this, amongst many other approaches. If someone can drop their electric bill by some 90% with a home solar energy system, that's awesome. Example: My highest electric bill was $160 one month, and used over 1000kW of power. Now, highest bill since my solar installation has been about $12,...but I also went through the house and did all LED lighting, a high efficiency air conditioner and furnace, and a high efficiency, wall mounted water heater. Now, I think I calculated my highest home energy use at 450kW,...but mostly it's been down around 400-425kW. So, even without doing solar,'s been beneficial to simply make the home more efficient, in general. I am looking at doing new windows for my next project. Getting all these things out of the way,...when I have the income to do it,...will pay off when I retire. As one gets up in years, especially as one becomes more sedentary, the metabolism slows down, and it becomes progressively more difficult to stay warm. Next thing you know you've got the thermostat set at 80* and you're sitting around the house with blankets on. How's that going to effect the heating bill? Windows, insulation,...all those things will need to be addressed. Getting old sucks,...and it can be expensive from the home utility bill perspective, so the idea of solar is a great one. Best of luck.

Tesla-David | 3 juin 2017

We downsized to 2000 square ft home in 2012, and added solar. We replaced gas furnace/water heater with electric heat pump/heat pump water heater, and conducted weatherization repairs to 1987 home to make it more energy efficient. This was the best money spent, as we have reduced our energy expenditure footprint from ~11,000 kW/year to 4,500 kW/year. We added 13.2 kWh solar array in 2012, and have been net positive for past 4+ years, producing, 204 percent during 2016, which included charging our MS. Our annual electric bill now with the energy reduction actions (insulation, LED, energy star appliances, LOE-366 argon windows, etc.) have reduced our annual electric bill from $1200+ to $160/year, and through net metering, we get an annual check from our electric provider $5,000/year for our excess production. We currently sell all the electricity we produce back to grid at $0.54/kWh and buy back what we need to run our home at $0.09/kWh. Our solar system will be paid off in less than 8 years, with the incentives in place in Washington State, and we live in Edmonds, WA, not the sunniest place, yet solar works very well here as I summarized above. I retired three years ago, and have never regretted our decision to go all electric and solar. We are on our second Model S, the first delivered on 1/2/13 and the second on 6/15/15, with a Model 3 on order, and I am currently wait listed for two Power-2 installations. Good luck with your retirement plans, and I would certainly recommend adding solar.

Bighorn | 3 juin 2017

Enjoy that deal while you can as it's clearly unsustainable and not available to 99%+ of the rest of us.

Tesla-David | 3 juin 2017

@Bighorn, I hear you and agree we have a great situation in the NW. With the cost of solar dropping >50 percent since our installation, solar is still the way to go even without the incentives Washington State has.

Bighorn | 3 juin 2017

Agreed, but clearly paying a 500% premium for wholesale electricity is bonkers.

Watt fun | 3 juin 2017

Bighorn, what you say makes perfect sense, except that sometimes what you don't see are the incredible spikes well behind the scenes. As unreasonable as 54 cents a kWh sounds, it might be that the peak spike alternative cost for the utility over a relatively short period might hit $25.00 a kWh, so then paying 54 cents for a limited number of kWh and limited numbers of small suppliers makes sense.

That being said--where I live we get most of our electricity from wind turbines, and top up mostly on inter-provincially imported hydro/nuclear electricity. The private utility and the remaining local public utility both have a more sensible deal. They pay the exact same amount (before taxes) for electricity sent to them, as they charge (before taxes). Everyone here pays a separate infrastructure and connection fee. For most homeowners, it would be about $28.00 each month, and *sensibly* that is not part of the debits or credits of kWh accounts. You pay that fee and nothing offsets it--as it should be. Just so everyone knows how much the break-even point is for maintenance and repair is.

Bighorn | 3 juin 2017

Point taken. Another reason why storage will supplant the peaker plant approach.

Tesla-David | 3 juin 2017

The incentive $0.54/kWh was put in place to support home grown solar/inverters made in Washington State. The incentive drops to $15/kWh for panels/inverters made outside of WA. These incentives are currently set to sunset in 2020. The WA legislature is currently debating what to do for solar going forward. Not likely that the incentives we have enjoyed will be as lucrative in the future, especially with solar becoming much more competitive.

Tesla-David | 3 juin 2017

Oops, $0.15/kWh

p.c.mcavoy | 3 juin 2017

I wish I was in the situation like some of you where I had to worry about how best to factor in such differences or opportunity to generate income via net metering. Some of us are unfortunate to live in states where at best utility will let me install such a system as long as I have good isolation to protect them, are willing to take my excess, but give me nothing in return. State also provides nothing in incentives, although maybe at least some minimal tax credits. I still love the idea of a Tesla solar roof/powerwall setup, and when the slate version of the tiles become available, may still give it serious consideration, but likely will struggle with a financial justification. While I hope a major windstorm does not come through and cause me serious damage to my roof, forcing me to consider replacement sooner than the roughly 7-10 years more that it will last, that's honestly about the only thing that would allow me to consider a financial justification to install the Tesla solar roof/power wall setup that I'd seriously love to consider. I may still be tempted in another year, once I have a better understanding what the tuition bills will look like with younger two daughters start college, even though I know I likely could never justify it from a pure financial perspective.

I'm sure the

SCCRENDO | 3 juin 2017

My 13.2 kW system has a payback of about 9 years and I am 3 years into it. I expect to be in my house for at least 6 years. I don't have the great payback that Tesla-David has as we get reimbursed kWh for kWh. The way I look at it is that I am doing my part to save the environment and if I sell the price of the solar panels is likely to increase the overall value of the house. I presently produce excess electricity in the longer daylight months, use my reserves for a few months and pay in small amounts Dec to Feb. One other side benefit is that the city's utility imports electricity from burning coal so I am contributing to cleaner Utah air.

Tesla-David | 4 juin 2017

I am with @SCCRENDO on my reasons for going solar. I am fortunate to live in a state that has great incentives to promote solar, but would have gone solar without the incentives for the reasons he stated above. I care about saving the planet, and having a miniscule carbon footprint, which we now have. I look forward to our Powerwall-2 installation, which will only add to that energy independence. It is sad to see how some states and energy providers are doing everything they can to discourage renewable energy adoption/use.

SUN 2 DRV | 4 juin 2017

vp said: "Because it increases the capital value of your property by 100% of the amount that you paid for it. Comment?"

That would be nice, but I don't think most real estate agents would agree...

And with the constantly declining cost to add solar, it's hard to imagine how your property value has increased by YESTERDAY'S higher price of adding solar...

And frankly some people don't like the LOOK of solar and for them you diminished the value of your property...

mark.willing | 4 juin 2017

Re: Will a home solar energy system increase the value of my home? Yes, per Fannie Mae and FHA.

Of course, as Sun 2 DRV noted, depends upon attracting the right buyer.

Mike83 | 4 juin 2017

A rough calculation is $1 Energy saved translates to an increase of$20 of property value. A 5kW system adds $30000 to value.

SCCRENDO | 4 juin 2017

@mark. Thanks. Good to know

vp09 | 4 juin 2017

Sun 2 Drv I saw that 100% stat back when I put up my first solar array in 2001. Real estate journal said 100% of cost for solar panels is recouped in increased sale value of home, 85% for kitchen remodeling, 50% for an added room, and zero percent for a swimming pool.

SUN 2 DRV | 5 juin 2017

VP: By the time I added solar to my house in 2010, the industry was no longer claiming that high a percentage boost in resale value. The LBNL study for 2015 does seem very bullish on increased resale value, but I still wonder how it could ever be 100% with the constantly declining cost of solar...

Mike83 | 5 juin 2017

If you sell your house does the NET metering transfer?

SUN 2 DRV | 5 juin 2017

Mike: That's a VERY good question. I'm about 80% sure I read that in California NEM status stays with the SYSTEM, even with a new owner... but a home buyer would want to verify that for sure.

Earl and Nagin ... | 5 juin 2017

Unfortunately there is no answer to that question since it can be changed by the stroke of a pen upon the whim of politics.

Haggy | 5 juin 2017

PG&E will pay me 3 cents/kWh for energy generated in excess of what I use over time. It's not much, and if I got extra capacity that I never would use, it would be an easy choice. But even if I spend only $200-$300/year extra for five years, even though it would be cheaper than paying for extra capacity, even if I get back only $50/year from PG&E for the subsequent 20 years, it seems as if planning for the EV makes sense. It might be break even at that point, but if I factor in any increased use that's unanticipated, I think I'll be ahead. Anyway, aside from the value of not keeping the money invested, the difference is getting close to the point that I'd save more by getting the system a month earlier and having one less monthly bill than it would be worth figuring this out in more detail.

m6bigdog | 14 juin 2017

I say; oversize the system to anticipate changes as it will never be cheaper to add watts as in the initial install.
1) System output power will degrade approximately 1%/yr so it will be down 20% in 20 years.
2) I anticipate electricity will become more expensive every year so the out years will cost you much more if the system does not generate enough to meet your future usage demands.
3) I anticipate more electricity usage in future years for charging vehicles and other home electrical products as more products draw 24/7 power (vampire loads).
4) I would not expect product efficiency will reduce energy loads to any significant amount.

Retirement advantage is to expense the photo-voltaic system now and reap the rewards of not needing to budgeting for electricity usage in the out years.