I'm considering having an electrician install a whole house surge protector. The house gets 200 amps from the grid. The surge protector would protect appliances and the new electric car (a Leaf). Some manufacturers claim that their surge protectors save energy. Is that because variable inductive loads can send energy back to the electrical panel and the surge protector can re-route that electricity back into the house instead of putting it back into the grid? If so, would the savings depend on our inductive loads? Our heating is geothermal so we have a heat pump and an air handler. Both I think are inductive loads.
No. That isn't their function.
A surge protector only kicks in when the voltage goes over a reasonable level (typically about 600V for the units I've seen), to prevent that excess voltage from damaging things downstream. It will help guard you against lightning strikes on the power lines and things like that, but it does not save power, and in fact probably costs a minuscule amount of power itself, to power its status LEDs if it has any.
A surge protector is really a fancy case around a few metal-oxide varistors (MOVs), which you can look up if you want more details on how they work. Plus a few extra components if it has a status light, though the MOV does all the real work and the status light just tells you it isn't necessary to replace the MOV yet.
Now, there are power strips which act to turn accessories plugged into them off when the main device is turned off. For example, powering down your PC would cause these to also turn off your printer, scanner ,or whatever else is plugged into them. I use one so turning off my amplifier turns off my whole stereo system. Since a lot of modern devices burn a bit of power even when supposedly turned off (so they can turn on instantly or respond to an IR remote), this process of powering them down completely does save some power. Some of these outlet strips also have surge protectors built into them. But the power saving function is separate from the surge protection, and you need to shop for one that has the features you need.
Of course none of that "avoid standby power" behavior is applicable to a whole house surge protector.
Since comments may not persist:
The other thing that may have gone into this question is that there are devices being sold which falsely claim to reduce your power usage. These are marketed by the same kinds of scam artists who sell miracle devices to improve fuel efficiency in cars,
DavidLevner has pointed out that the National institute of Science and Technology has explained why the phase-correction-device-as-power-saver argument is based on a misleading description of the basic physics: https://www.nist.gov/news-events/news/2009/12/nist-team-demystifies-utility-power-factor-correction-devices. Thanks, David!
A central surge protector may save energy compared to individual surge protectors on every wall outlet. I'm not sure that you'll see that saving on the energy bill, tough.
The reason is that surge protectors usually provide a small capacitive load. Lots of wall outlet surge protectors in your home will cause a noticeable load.
This capacitive load of lots of wall outlet surge protectors may can also cause a noticeable current in your grounding/earthing. The foundation earth electrode may corrode prematurely.
Yep, talking about lots of individual wall outlet surge protectors (or lots of surge-protected power strips) here.
Regarding any surge protector where the
scammer manufacturer claims "energy savings"...stay away from these, they can't be legit. If you're getting your distribution box rewired, you can have a surge protector installed. The main cost is the work of the electrician rewiring the box (in some legislations, the electrician also needs to hold a special license if he works in front of the electricity meter, where such a surge protector is usually installed). A three-phase surge protector from a reputable brand is around 200€ (German prices here, as that's where I live). Prices can vary a lot; you may encounter products from reputable brands in the range from 140€ to very well above 1,000€. Regardless of price, it will not pay back via the electricity bill, but it might make you sleep better. Especially if you live a region where power lines are still above ground.
Does the ‘surge protector’ you’re considering resemble the one discussed in this answer?
If so, stay far, far away. It will not save you money, and may even cost you money while providing bupkis in terms of protection for your house.
Will a whole house surge protector save energy?
It won't save energy that you see on your power bill. But you'll still save money.
It saves energy indirectly, by protecting equipment from damage. Manufacturing replacements certainly takes energy and all costs are passed to you, to purchaser. So, while it doesn't save you energy, it saves you money that you'd spend to pay someone else for the energy and other resources they have used to produce replacements for damaged devices.
On contrary, it will cause the house to use minimally more energy.
A whole house surge protector uses varistors to clamp voltage when it goes beyond safe limits. Those are non-linear elements, as they don't suddenly turn-on at specified voltage, rather they begin to 'let through' the current more and more as they approach the set voltage at which they conduct.
As long as they are the correct voltage for your power grid, everything will be fine, but there is a minimal current going through them at nominal voltage. The currents are really small and wont show on your power bill, but it is incorrect to claim the device makes the house use less electricity. If any manufacturer claims that, I suggest to stay away from them.
If you want a surge protector with zero leak current, sparkgaps provide that. A good quality whole house surge protection should have both spark gap and varistors, but due to space constraints we usually install varistors only.