Comments on: Valuing Energy Efficiency in the Electricity Market

By: David Butler

David Butler — Tue, 24 Nov 2015 09:58:12 +0000

@Justin, I do know someone
@Justin, I do know someone who ducted attic air directly into the intake of their HPWH. As Allison said, this creates positive pressure on the house (typically several hundred CFM), which forces an equal amount of conditioned air to exfiltrate through the envelope. It also increases the discharge temp of the HPWH, thus reducing it’s cooling benefit. My friend mitigated these effects using a timer to operate the HPWH early in the day in summer before the AC would normally kick on, and later in the day during winter after that attic temperature peaks. But I’m not convinced this is a net-positive strategy.

Regarding PV vs maximum current draw… Your comment focuses on what happens when PV is producing power. But the utility infrastructure still has to support peak draws when there’s no sun. The highest peaks for the typical home can and do occur in the morning and evening when the sun is low or during a mid-day shower. This is true in summer and winter.

By: Allison Bailes

Allison Bailes — Tue, 24 Nov 2015 03:07:00 +0000

In reply to Justin Fowler. Justin: No, it doesn't make
Justin: No, it doesn't make sense to use a fan to bring heat from your attic to where your water heater is. If you have a heat pump water heater, some of that heat would go to your hot water. You could try ducting straight into the intake of the HPWH to increase the amount, but even if you were able to do this without increasing the cooling load on the house, you'd be creating a pressure difference by bringing air in without exhausting the same amount of air. Putting the HPWH in the attic would be better for efficiency, but I personally don't like the idea of a water heater in the attic. If you live in a hot place like Las Vegas or Phoenix, you could put a HPWH in the garage and use the heat that way. If you're just talking about a conventional water heater, however, it's an even worse idea to bring heat from the attic into the house. It's not going to help your water heater but it will make you AC run more.

By: Justin Fowler

Justin Fowler — Tue, 24 Nov 2015 02:54:34 +0000

EE will always contribute to
EE will always contribute to whatever plan you are on. It is a result of rising utility costs. Let’s just concentrate on electricity.
What are the main causes of rising electric rates? Maintenance of the infrastructure of the delivery of electricity. Sure, profit is part of it but taking care of transformers, power lines, sub stations etc costs money. Some studies mention up to 50 percent.
Will those costs go down? Hell to the no!
When it comes to rooftop PV, a couple of points: Saying that PV has little or no impact on a home/ business’s maximum draw is incorrect. Electricity distribution through the ‘grid’ is great but up to 15 percent of the electricity never makes it to your home/business. Guess what? With rooftop solar and net metering, the electricity you are not using goes to your neighbor. I would say that is more efficient. As for drawing power with PV…from where? The PV power first goes to your home/business then goes back to the grid. As for Bob, you are exactly right, target peak. And for David, tou is a result of higher demand at certain times of the day/year where most people are using a lot of electricity for different reasons and the grid is over worked due to delivery limitations and inefficiencies causing black outs, more labor dollars, more maintenance, part replacements etc. Let’s not get complicated: It’s a wire delivering us electricity from 100’s of miles away and during certain times we want our washer/dryer, AC, 3 big screen TV’s, pool pump and hot tub to be working all at once. Rooftop PV obviously eases the workload on that power plant and wire.
David and Allison, I read your articles on attic heat, what could I do to use attic heat to heat my water heater without putting a heat exchanger in my attic but rather using a fan to bring the heat closer to my water heater downstairs through a pipe and then to my water heater, or does this even make sense?
Regards,

By: Bob

Bob — Thu, 19 Nov 2015 07:42:58 +0000

In reply to David Butler.

Time of Use and Variable Peak
Time of Use and Variable Peak Pricing will replace the old “flat rate” as smartmeters become more common. Utilities can price the TOU/VPP rates aggressively so the typical customer can save considerably by reducing peak use.

In our area we have smarthours, which is a summertime VPP program. Over 100,000 have signed up since it’s inception in 2012. http://www.ogepet.com/programs/smarthours.aspx

By: David Butler

David Butler — Thu, 19 Nov 2015 04:25:19 +0000

If the objective is to
If the objective is to forestall grid and generation infrastructure costs, it should be obvious that measures designed specifically to address peak load (especially smart controls and storage) will be more effective than more general EE measures designed to reduce consumption. So there’s a potential conflict, or at least poor correlation among solutions that aim to reduce CO2 emissions versus solutions that aim to optimize generation and distribution infrastructure investment.

What’s now clear is that rooftop solar (PV) and net metering work against the latter objective, since the impact is far greater on a home’s overall consumption than on its maximum load. In fact, PV typically has little or no impact on the maximum current a home might draw at any given time.

On the other hand, certain EE measures do have some impact on peak, but EE also amplifies the disparity among households in terms of their relative contribution toward infrastructure costs.

A tariff with a demand (kW) component would be the most equitable way to address this, and would provide the correct price signals for various energy related investments. However, unless such a tariff is mandatory, it’s unlikely to have much of an impact. Politically, that’s not gonna happen anytime soon.

By: Jim Gunshinan

Jim Gunshinan — Thu, 19 Nov 2015 02:56:57 +0000

I'm wondering if Matt or
I'm wondering if Matt or anyone else has done some modeling of the effect of ee on load profile in a utility area? SMUD did a study a while back that showed the amount of load shed during peak use due to a new housing development where homes all had PV installed.

By: David Bopp

David Bopp — Wed, 18 Nov 2015 20:23:55 +0000

In the Pacific NW this has
In the Pacific NW this has been a requirement for a while now. Energy Efficiency is required to be considered an energy source on par with any other. In addition, as future power plans are created to meet the changing market energy efficiency not only has to be considered but is required to be given a 10% bonus compared to all other sources. You can find out more here: http://www.nwcouncil.org/energy/powerplan/ The 7th power plan is in draft form at this time and available if you want a little light reading.

By: Howard Katzman

Howard Katzman — Wed, 18 Nov 2015 20:07:22 +0000

Matt makes some key points.
Matt makes some key points. They question is HOW to get EE inside the store, particularly here in Georgia. Let's start a discussion about that.