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Electrify Everything? Part 2.

Heat Pump Water Heaters in Multifamily Buildings

In Electrify Everything? Part 1 that I wrote several months ago, I mentioned that integrated tank heat pump water heaters (HPWHs) can work well in single family homes — even in colder climates. For example, we see quite a few installed successfully in basements in the Northeast. These devices remove heat from the surrounding air, so there needs to be enough heat in the basement air for them to work effectively. During the winter, a home’s space heating system probably needs to work harder to make up for the HPWH. In the summer, the HPWH provides a bit of extra cooling and dehumidification. We put together some guidelines a few years ago on how to get the most from these systems in single family homes.

Image of heat pump

Some places where I’ve seen problems:

  •   Installing a HPWH in a basement closet. Even if a closet has louvered doors, there’s not enough heat/air for a HPWH to work well.
  • HPWHs are relatively loud. If there’s a finished part of the basement (e.g., bedroom or office), the noise can be disruptive.
  • Sometimes there is trivial heat gain to the basement (from outdoors, mechanical equipment, etc.). When a HPWH removes heat from the air, such a basement can quickly become too cold for the water heater to work efficiently (and too cold for comfort if someone uses the basement).

But overall, HPWHs in single family basements can work effectively.

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Five Steps to Get Started with Net Zero Energy Buildings

Net zero buildings are becoming increasingly popular, and some jurisdictions, such as Washington, DC, are projected to become code within the decade. Massachusetts will also begin development of a net zero building code. Curious if your building is a net zero contender or what it would take to reach net zero targets?

What Does it Mean to be Net Zero?

The term “net zero” commonly refers to zero-energy buildings. In simple terms, a zero-energy building is one that produces as much energy as it consumes on an annual basis. There can be nuances and caveats to this definition, but for now, we want to bring you up to speed on five key net zero energy strategies to consider if you’re interested in developing a net zero building.

1. Maximize space for on-site renewable energy.

How tall is your building?

  • Any building over five stories will be challenging, if not impossible, to achieve net zero with on-site renewable energy production alone because building energy demand will likely exceed available site area. Maximize your solar with a smart layout and consider if other renewables, such as geothermal, are possible.

    Image of roof layout

    Typical roof layout for multifamily building, including necessary setbacks for fire access, mechanical equipment access, and shading from bulkheads. Fire access is based on FDNY guidelines.

Do you have other spaces available for solar photovoltaics (PV)?

  • Your development may have a separate parking garage or parking lot on site. These are great places to install a PV system, which can significantly increase the amount of on-site renewable energy production and help make achieving net zero more of a reality.

Do I have to have all renewables on-site to be net zero?

  • If you don’t have enough room for on-site renewables, you can look into purchasing off-site renewable energy options, such as community solar, power purchase agreements, or renewable energy credits.

Now that you’ve considered renewables, let’s move on to net zero building design considerations.

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The Impact of Energy Star’s Portfolio Manager August 2018 Updates on NYC’s Local Law 33 Grades

Image of Letter Grades from SmartBuildings.NYC site

Letter grades are coming!

NYC’s building owners and real estate management firms now have one more thing on their plate to consider: Local Law 33 of 2018. LL33 compliance will assign letter grades to buildings required to benchmark energy and water consumption. The energy efficiency score will relate to the Energy Star Rating earned using the U.S. EPA Energy Star Portfolio Manager (PM).

The law will come into effect on January 1, 2020, and will utilize the previous year energy data to set the energy efficiency score and letter grade as follows:

Picture of Buildings, with quote "Your energy letter grade will be posted in your lobby in 2020. Are you ready?"A – score is equal to or greater than 85;

B – score is equal to or greater than 70 but less than 85;

C – score is equal to or greater than 55 but less than 70;

D – score is less than 55;

F – for buildings that fail to submit required benchmarking information;

N – for buildings exempted from benchmarking or not covered by the Energy Star program.

Why is my letter grade lower than expected?

Property owners should be made aware that if their property earned an energy efficiency score of 75 for the 2018 Benchmarking filing, the new score for the 2019 benchmarking filing may have fallen as much as 20 points. In LL33 terms, what could have been a letter grade “B” could now be “C” or “D” based on PM updates implemented in August 2018. Property owners will want to learn how the Energy Star PM update will affect their LL33 letter grade.

To understand the correlation and impact that the August 26, 2018 Energy Star PM update will have, it is important to look back at what took place as part of that update.

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Replacing Indian Point – An Update

Last year, we wrote about New York State’s plans for replacing the 2,000 megawatts of electricity provided by Indian Point. As of March 2018, Indian Point is still slated to close in April of 2021. The New York State Independent System Operator (NYISO) will reassess the plant’s retirement plan later this year and will continue reassessing this plan regularly to ensure that the state’s electricity needs are met. At the time of the initial closure announcement, the replacement plan leaned heavily on increasing transmission capacity to New York City, particularly via the proposed Champlain Hudson Power Express. However, there were still some gaps between downstate’s power requirements and the total power available without Indian Point.

Indian Point Image

In December 2017, NYISO released an Indian Point retirement assessment report and concluded that downstate’s power requirements will be met, providing that three proposed power plant projects in New York and New Jersey are completed on time. The CPV Valley Energy Center will be a 680 MW natural gas-fueled combined cycle plant in Wawayanda, NY, opening later this year. The Cricket Valley Energy Center will be a 1,100 MW natural gas-fueled power plant in Dover, NY, and is slated to begin power generation in 2020. An additional 120 MW of capacity will be added in Bayonne, NJ. As of the end of 2017, NYISO has determined that all three of these projects must come online by 2021 in order for the Indian Point shutdown to go through.

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Power vs. Energy

I can get worked up about units, and this can really annoy people. It especially annoyed students I taught in grad school. I was pretty tyrannical when grading; they always had to include units in their calculations. They could have all the right numbers, but they didn’t get full credit unless all the units were right too. I have no regrets about being such a stickler, because I see tons of confusion about this in the building & energy fields. So here’s a rant about one of my pet peeves: power and energy.

Question: What’s the difference between Power and Energy?

Is this some kind of philosophical question? A koan to meditate upon? No. There’s a real answer (in the engineering world at least). Power is the rate of energy.

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