Heat pumps are a good solution in areas where natural gas isn't available and/or electricity is relatively inexpensive. Unfortunately, neither is the case in the Evergreen/ east foothills where you live. They do work fine producing heat but using setbacks (as you describe) can be troublesome because the "warm air" produced is not as warm as from a gas furnace and so the recovery from a setback to the set temperature takes much longer. From what I've read, many HVAC experts advise setbacks of no more than a few degrees during heating season for a house that's normally occupied (as distinct from a vacation home not used regularly).

I live in your general area. Unfortunately, PG+E electricity rates are among the highest in the country. Whether you're paying them for the electricity to heat your home, or paying for a large-ish solar panel installation needed to supply your intended needs, I'll guess it would cost you quite a bit more to heat with a heat pump compared to a gas furnace. Get a heat pump quote (including an estimate of electricity consumption for one year) and get a quote for the solar equipment. I think you'll find that unless cost is no object because your decision is based on your own political or moral views (which is fine with me), going the route you suggest is going to be VERY expensive and much more so than just the conventional gas furnace approach.

If being thoughtful to the environment is important to you, be sure to buy a high-efficiency model gas furnace. In the same way but to a much lesser extent, you may not recoup the added cost for installation and more costly equipment compared to the standard 80% efficiency types but a desire to get the most efficiency out of the fuel can be satisfied.

A heatpump might be an economical alternative with solar energy generation. Just be careful - electric companies are continually reducing the amount they will pay you for eletricity put back into the grid. Also, while initial installation costs may be defrayed by tax breaks, credits and discounts, repairs and replacements are fully on your dime. A neighbor of ours recently had to replace almost half of their panels after only 5 years at a horrendous cost, eliminating any benefit they were expecting. The installing company had gone out of business and the utility said "not our problem"!

As previous posters have written, it is a matter of numbers. In addition to cost to purchase equipment and to fuel it, the contribution of wear and tear on the equipment should be considered. If, outside of fuel costs the wear on a heat pump is more expensive than than that on a furnace, that is one vote for a furnace.

Yeah, that's why I was hoping to get some info from someone in a similar situation. Otherwise it's quite hard to take all assumptions into account.

Of course it would be best to speak to someone who's done what you want. If your's is a conventional house (and not like a special showplace in Portola Valley), I think you may find installations similar to what you're thinking about to be very few and far between. For good reason, my expectation is that your proposed approach would be rather more expensive than using a more common approach. Other than people who can afford to choose to go that route as a matter of principle or as a personal statement without regard to cost considerations, it's an unattractive approach in this area because of the high costs to install and high costs to operate.

Less than a decade ago it made sense to install heat pumps rather than gas furnaces in many places where it does not today. That change was caused pretty much by low gas prices. It all depends on gas vs. electric prices and the lifetime cost of the equipment. I think that heat and cooling are relatively easy in your climate so efficiency is not as important as in some other places. That is doubly true if the home has good air sealing, insulation and other energy efficient characteristics. In other words, it might not be worth ringing your hands over. If you can't make the calculations yourself by doing some research on the internet or elsewhere, there may be a local energy efficiency program administered by local government or public utility. Often they pay all or part of the bill to hire a local energy rater to do a top to bottom evaluation of homes. Energy raters recommend where to put your money for the best return on your investment, insulation, air sealing, new windows and what kind of heating/cooling appliances and water heaters. They should also know about local subsidies for energy improvements. Conventional wisdom in these things is very often wrong. If it is free or heavily subsidized, you have little to lose and a lot to gain. Even if not, it is probably worth it. Look at resent.org and BPI.

I am facing the same dilemma, my concern is what if heatpump can't keep us toasty in winter months. We try to keep our house at 70 degrees F most of the time.

You could go for a hybrid heat system. I'm probably going that way with a cheap gas furnace for backup.

Can a heat pump keep you warm in winter months? Arithmetic is your friend. There is no dilemma. Ability to heat, and cost to do so can be calculated. In a mild climate, the ability to heat with a heat pump was proven decades ago. Colder weather performance has and continues to improve.

What do you mean by backup? Do you want a second heating system in case the first one fails? Historically, that is not done as it costs too much. Do you mean a means of heating while the heat pump is in defrost mode? I've never seen the need for it in my home. I have mini splits and that is a little different as I have three systems and not all defrost at the same time. In addition to that, I have minimal heating needs in the Gulf South. Deciding the best way to heat boils down to running numbers.

Perhaps but if one also has solar panels in mind then the math might change. Others might also be concerned by environmental impacts.

Backup as in when the heat pump is not very efficient due to low temps.

I agree, tigerdunes, that is where the "cost to do so" entered in. It can't be stressed enough unless budget is effectively unlimited. In addition to fuel cost, the cost to operate the equipment is often forgotten. How does the average annual cost to run a heat pump vs. furnace/AC combo compare over the lifetime of the equipment?

Nick, it would pay to check design temps for your area, but the way you describe it, from a heat pump perspective, you don't have low temps. Heat pumps have been used for decades in areas with extended periods of temperatures below freezing. That is not to say that is an economic blessing. Many of these systems were installed in times of higher gas prices and the owners are either stuck with them due to building design issues, or too uninformed to install a furnace. They heat fine and today's systems are even better. They sometimes cost the owners a bundle, however, compared to natural gas fuel.

ionized, do you mean resnet, not resent?

One other thing to consider if options are available, the life of a properly maintained furnace is longer than an outside HP condenser.

IMO

Another consideration is that heat pumps are not commonly found in the San Jose area. Perhaps the servicing isn't a significant matter but finding a contractor with expertise around here will be a challenge.

Are you using the solar panels to justify the heat pump, or the heat pump to justify the solar panels? Solar panels aren't all that cost efficient either, unless you're planning on being in your house for the next 20+ years.

Yes, mtvhike, thank you. I am going to have to blame that on a spell checker. Unfortunately, it looks like I am beyond an edit cut-off. For residential energy raters:

BPI

resnet

The idea of choosing a HP to take advantage of solar panels seems disingenuous.

Backup does not refer to another heating system. It usually refers to a Dual Fuel System, a high eff heat pump with a high eff fossil fuel furnace. Fuel could be nat gas (preferred), propane, or home heating oil. One has to analyze operating costs between the fuels versus electric heat pump.

i have a dual Fuel Trane system. There was operating cost leverage btw electric and nat gas some years ago. No more mainly because of regulated electric rates increasing and market driven nat gas pricing on decline. I have cut off HP and use high eff nat gas furnace exclusively for heating. I certainly covered the extra cost for the HP condenser over straight AC in the first 5 yrs of ownership. Looking back probably not worth it. But I do have some flexibility which I don't use.

IMO

Given your area in California, typically high electric costs of 20 cents or more a KWH, what sounds like a more moderate climate a heat pump may not be a bad idea.

Heat pumps work best in climates that 'typically' stay above freezing outdoors. This doesn't mean a heat pump won't work in freezing weather, just not as good as a climate that typically doesn't freeze.

As far as how long a heat pump lasts versus a gas furnace? How old are you? How long to you plan to live at this home? Certainly you could have more trouble with a heat pump repair wise, but I don't know if that is a reason not to consider that option.

The other part of this is if you are trying to negate your gas bill you must also look at other appliances in the home, such as water heating methods, possible gas dryer and gas stove.

With that said solar arrays perform best in areas of high electric costs, it's true that the utilities continually change what they will and won't pay you for electricity dumped back on the grid, but in a high electric cost environment what other choice you have other than pay the high rate?

I really can't say for sure there is truly right or wrong answer here. You would have to know where prices are going for your area to truly know for sure. What electric / gas prices are today doesn't mean they will stay that way for long.

"it's true that the utilities continually change what they will and won't pay you for electricity dumped back on the grid,"

It hasn't changed at all here in PG+E land, Austin, and I think it's the same in other investor owned power utility areas. How it's always been and how it was the last time I looked, nothing is paid. On a 12 month cycle basis, a customer "banks" negative use (production in excess of use), usually during the summer months, and can use that kwh credit during the winter months when use normally exceeds production. Any excess use is charged in a bill, excess production receives a Thank You and that's it. We have a two tier pricing system and the biggest payoff is to install equipment to offset usage that would be paid at the higher tier. Installing too large an array is really a waste of money since nothing is received for excess production.

Rules for grid-tied solar are different for every state and maybe vary even within states. Some places you get paid back the excess when you end your service (move out, and sell or rent the house). Other places, there is NO compensation for excess power. Still others give you back at a reduced rate.

A lot depends on the politics of the utilities commissions. I think that a 1:1 payback is rare. To my way of thinking, since solar is produced in a peak demand period in a cooling climates, producers should get a higher rate, or at least equal to what they pay per kWH at night. The other thing that bugs me is that homeowners that install solar are at the mercy of whims of the utility commissions. The deal with the utilities can change overnight. Compare that to other power producers that build generation capacity (gas turbine, nuclear, coal,...., even solar farms) They get guarantees that are very long term.

In my case, in northern NY (NYSEG), the basic rate is less than $.05/kwh. In the last 30 days, I've used 3500 KWh, so the cost is $175 (+ $15 basic charge) for resistance heat with the outside temperature between 0 and 25°, which I think is very low. That's why I don't want to spend tens of thousands of dollars for a heat pump, or $45,000 for solar panels, especially now that there will be a 30% tariff on imported panels.

Yikes, I used 415KW (double the usual because of Christmas lights) and thought that was a lot. Do you use it for heating?

Yes, savolu, my heating is totally electric resistance, and that's my total heating cost for a cold month.

Mtvhike what is your square footage conditioned space? My impression is that your home there is a new and efficient structure. Do you characterize it that way?

My numbers are rough and should be checked if anyone is serious about making this choice. If I am calculating properly, gas at $10/MMBTU would cost $132 to heat that home with a 90% efficient furnace or boiler. (I know that you don't have access to nat gas, but bear with me.) that would cost you, maybe $7,000. That would be 4 decades to pay back the additional equipment cost assuming 4 months at that heating cost given above.

If a heat pump system costs $10,000 and I think that is high, it would halve your heating costs at a COP of 2. That would take a century.

OK, go solar. NREL number is 3.22/watt today. You'd need a 3 kW system to heat with resistance heat. For solar costs $3.22/watt (NREL) for a 3 kW system. That is close enough to $10,000 to apply the heat pump ROI estimate.

As I like to point out, if you have an efficient structure, your heating fuel choice matters little. Now add in domestic hot water costs.

ionized, on the issue of residential solar, I find myself in the rare position of having some understanding for the position of the utility companies. And believe me, being in the territory of PG+E, it's hard.

The utility is responsible for maintaining the adequacy of both base loads and peak demands. In California, they're required to integrate with the state power agency that manages, balances, and redistributes supply and demand. The utilities have no ability to manage or predict what residential (or even commercial building) installations may or may not put into the grid on any given day. I think allowing users to offset their own usage by banking the excess is about all that's fair to expect. And this doesn't even cover the issue of whether such users (who on a net basis may not be buying any power) should or shouldn't have a supplemental charge to cover their share of the costs of maintaining the distribution network that they benefit from but don't otherwise pay for to the extent others do.

My main problem is the lack of a long term agreement for what involves a substantial investment on the part of the homeowner.

Furthermore, sure, there should be some charge to anyone that uses network power, but the cost can be calculated the same as transmission (vs. generation) costs are now. We are out of the dark ages with figuring costs and passing them on to specific customers. Just do it, POCOs, and stop setting up that straw-man argument.

Peaking is always a problem, but what capacity is available is not going to change much from day to day apart from the weather and that is predictable. In my neighborhood, when the sun is shining strongly is when power is needed the most, period. PV is a great way to provide that. It responds faster than gas turbines.

The POCOs have whined and publicly wrung their collective hands for years saying that PV is a bad idea and not practical and continue to do so while, more recently, they lay out their own relatively vast centralized PV fields. Those fields are going to be more susceptible to cloud problems than distributed residential roof-top installations and suffer from the same high transmission costs as their other generation types. Note that I've seen calculations that indicate that if I install rooftop PV, it could benefit my next door neighbors more than me. I make the investment and they could get the benefits of collective transmission cost decreases that the utilities could pass along to all users.

These issues are not nearly as simple and the solutions not nearly as obvious nor straightforward as your comments would suggest.

Did you look at the thread titled, "Bosch BOVA60 Heat Pump System"? That guy is running his new heat pump off of solar panels so he might have some good information to share on this topic. BTW, that Bosch Inverter looks like a nice system at a decent price.

Elmer, I am up to be educated by you or if you could refer me to some resources from anyone not directly connected or funded by the power industry.

It hasn't changed at all here in PG+E land, Austin, and I think it's the same in other investor owned power utility areas. How it's always been and how it was the last time I looked, nothing is paid.

Ok Elmer, I stand corrected but I was really only referencing what I know to be true about my area in Texas. There is a strong energy presence in Texas so far as they named a section of town here called 'The Energy Corridor'.

So I wrongly assumed that it might be similar for California.

I suppose PG+E is your producer / maintenance provider of the grid? Then do you buy your power from a myriad of middlemen companies that bill you?

This is mostly the way it works here in my area. The producer Center Point Energy produces and maintains the grid, they charge for energy production is typically $03.5 cents to maybe $04.0 cents call it the energy charge. This charge is typically passed on to the consumer thru the middle man that bills you.

The middle men who sell it to you ( the home owner) current 'actual' prices run from 8 or 9 cents a KWH to maybe as high as 16 cents a KWH depending on usage typically. The 16 cent offering is typically skewed toward those gimmick offerings in which certain times of the day the KW's you use are free. In many cases the more energy your home uses here, the better the rate you get. If your power consumption falls below 1000 KWH per month, you will pay the higher rate here.

So because of this: If you use a lot of power here, your costs could actually go up the more energy efficient practices you use / or retro fit to your home to lower your energy bill. If you are at around 2000 KWH's per month here (Katy, Texas area) and you make energy efficient changes and drop below that amount of usage your bill could go up due to the higher electric charge you might be faced with.

The number of middle men here selling power is as long as the traffic lines you sit in everyday to get home. The myriad of schemes 'plans' they use to sell power to you is ironically just as long or longer. The term of the contract could be month to month on up to maybe 3 years. Except for those conditions, the schemes are always changing here. Most plans here are 1 year terms after the year is up if you don't sign a new agreement you revert to month to month in which your rate typically goes up and can do so each and every month.

Throw in solar grid and you will see even more variances here as to what they pay you for energy dumped back to grid. In most cases it's next to nothing considering the investment you made for the solar energy you are producing.

No, Austin, there's no option to procure electricity from a source other than PG+E. I understand how that works in other places but we don't have that here. A 2000kwh monthly usage would produce a bill well over $500, even in the summer, even in the hottest areas where baseline (lowest tier price) allowances are most generous. If all electric (no gas heating, not common), it would be a bit lower in the winter. Not much.

Ionized, rate setting and utility management by PUCs are political whether you like it or not. You're welcome to prefer the political propaganda of the solar industry and ecology groups to the same coming from the utility side but as with most issues for which vested interests are involved, the desirable outcomes lie somewhere in the middle with a compromise. You need to read both sides to understand issues.

One thing for sure is that the Public Service Commission in Louisiana is in the pocket of the utilities. There is no middle compromise. The Commission only responds favorably to consumers when threatened with lawsuits. They have absolutely no shame and I don't understand why voters put them there. Maybe that is, at least part of, what makes me a bit sour in this area. I once talked to my region's rep on the panel in one of his town meetings. He answered my question with a really stupid pseudo legal answer when it required a technical one. He's a lawyer and I felt like asking him if he got his law degree at Sam's Club.

Compromises can sometimes be avoided by creative thinking or looking to how others are doing it outside of our closest sphere.

So in Louisiana they're elected. In California commissioners are appointed by the governor. So as I said, these are political positions in both cases.

Such commissions are frequent targets of lawsuits no matter what. Why do your fellow citizens elect and re-elect office holders who aren't acting to represent the views of the people they represent? Or are they?

Yes, of course. And state and local officeholders too. That's why my votes are usually restricted to referendum items and bond issuance approvals/disapprovals. When a ballot offers me no clear better choice for a particular office, I move on and don't vote. It doesn't help but I feel less personally culpable for later events involving someone I didn't support.

That's been happening a lot for me lately.

Sometimes I feel that way too Elmer. Why vote for the dopes, it only encourages them. In this case, I would not doubt that industry money is involved in ways that I don't like to think about.

The Louisiana PSC is viewed as a launching pad for political careers. It is an entry level elected job in other words. (That is what people say but I have no personal observations that indicate that it works.) LA is heavily weighted by Rep/conservative voters so, or the most part, if a commissioner votes for anything that smacks of "green" (no, not that kind of $green$). They'll never get elected to even a dog-catcher position for their next phase if they leave the PSC. The fight for net metering and anything else that rooftop PV needed was apocalyptic and continues.

Renewable energy has some friends on the PSC and they work hard to defend net metering from constant attacks. At one point, the PSC had a member or three that would not give up on their attack in state subsidies for renewable energy. The fact is, that's none of their business, but the legislature's portfolio.

For a while, LA had the most generous state subsidies in the nation for homeowner renewable power. That happened though a chain of events that resembled some that inspired Niccolò Machiavelli. More recently, however, the cash-strapped State stopped paying the tax rebates they they had already committed to. Homeowner had to fight to get the money promised to them for equipment installed long ago.

Does the original poster have information about what s/he decided, and how it went?? I am looking at exactly this decision in San Francisco. Would like to switch from a very ineffecient gas furnace system in an old house with no insulation, as part of a remodel to an electric heat pump, but finding very few who have experience installing, and really any local information.

Never lived in San Jose, but have visited some number of times. I thought that heat was needed only a half dozen evenings a winter.

Is that correct?

We have several months during which the average overnight low is in the 40s.

We have cooler wintertime temps than coastal SoCal. A human phenomenon is when the average temps somewhere are mild, when it gets cooler (which around here I would say is the mid 60s or below) for many people out come the jackets, scarves, sweaters and hats. I don't think people tend to overheat their homes as I've experienced when visiting the Mid West and East Coast but neither do I think they're tolerant of it getting too cool. Some are, some aren't.

I don't think your "half a dozen" nights a year suggestion would even apply in San Diego, where I think you mentioned you lived for awhile. Low temps are higher there than here but still it's cooler in the winter than in the summer. There as here, people seem to act like the temp goes from warm to cold without stopping at cool.

In the end I went with a hybrid system just in case: heat pump and backup furnace. The heat pump is doing it's work (both heating and cooling) just fine.

Do you have solar panels?

I'd be curious to know the approximate size and age of your house and what your PG+E bills have been in Jan-March.

Thanks

Do you mind if I ask who did your installation? I'm trying to get bids in SF and am having a hard time finding anyone who has done this before.

" I don't think your "half a dozen" nights a year suggestion would
even apply in San Diego, where I think you mentioned you lived for
awhile."

Lived there 1984-1989. Confirmed with my wife... maybe 6 nights a
year we ran heat... I lived in Del Cerro section. Used A/C maybe 3-4
nights a summer... typically during a Santa Anna.

Confirmed with
my wife tonight... 5-6 nights a winter for heat. 3-4 times a summer we
ran A/C. Pool temp 71-72 degrees in summer with no pool heat.

Wife drove a 1956 TR-3 Roadster with no heater and the top always down year round.

I've only recently (last 5 years) started spending more time in San Diego but the locals (real locals) tell me the weather has noticeably changed in the last 10 years. Summers are hotter and more humid, winters less change but a bit cooler. We used the heat a fair amount during December-March visits. A fair amount is relative, maybe a 15 minute warmup most mornings?

Air conditioning, not all that common in coastal areas (where our place is) is now a standard feature in new construction and more frequently retrofit into older places that didn't have it. That per the HVAC guy who did such work for me there a few months ago.

Alissa, yes, most installers were not very up to speed on heat pumps. I used Global Heating & Cooling Services.

The heat pump (in heating mode) and solar panels have only overlapped for half a month so far. This winter will be the first full test.

" And in less than an hours' drive, you can experience all four different San Diego microclimates - coastal, inland valleys, mountains and desert. Some residents enjoy the best of all worlds by spending their summers at the coast and their winters in the desert. "

San Jose is also known for its micro-climates. No one here can know more than the OP about his or her precise situation.

San Jose Micro-Climates

I did not live on the coast. As I said, I lived in Del Cerro.

I don't think the Santa Clara Valley has microclimates to the same extent as other parts of the Bay Area. If you want to see a microclimate in action, drive from Orinda to Oakland or better still Treasure Island. 15 minutes and 25 degrees.

In San Jose and the rest of the county - the northern part nearest the Bay - a bit windier, a bit cooler sometimes (5-8 degrees on a summer day, not much), a bit less rain. To the south and near the hills - a bit warmer (as above) a bit more rain, a bit less wind. Near water is always windier than at a distance.

SDGE (the power company) considers Del Cerro to be a mile or two at most out of its "coastal zone" that starts at the beach and ends around the 805 at that point for power pricing purposes). As I said, "Air conditioning, not all that common in coastal areas (where our place is) is now a standard feature in new construction and more frequently retrofit into older places that didn't have it. " So if you consider Del Cerro inland, that comment may not apply to your experience. But it's hotter there now too.

Feeling argumentative?