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Prof M Keith Sharp ScD PE

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Posted By M Keith Sharp 06-03-2024 08:16 AM
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Jay, Good question. To serve all loads with electricity by our climate change deadline of 2050, we probably need even more new lines and need to replace many existing lines for higher capacity. That is why I think we should consider offsetting some of these loads with ambient energy. Heating and cooling ...
Posted By M Keith Sharp 06-03-2024 07:51 AM
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Bob, I like the max heating/cooling load limit. The original Passive House limit of 10 W/m^2 is a nice round number, and allows ~100% ambient conditioning in many climates with south glass of 5-10% of the floor area and a reasonable amount of thermal mass. The thermos bottle just needs a few south ...
Posted By M Keith Sharp 06-02-2024 01:23 PM
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Bob, I agree with most of what you say. The main issue is "cheap batteries." Batteries are not the whole picture. The latest estimates for a 100% renewable grid are $8 - $21 trillion, which includes the other important pieces, namely renewable generation, transmission lines and utility-scale storage. ...
Posted By M Keith Sharp 05-28-2024 08:28 AM
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Hopefully, I have made my point that, even though it can be challenging for some existing buildings, ambient conditioning isn't just for new construction. My family have been builders for four generations that we know of. Maybe longer if we dug into ancestry. So I know a bit about remodeling. Thumbs ...
Posted By M Keith Sharp 05-27-2024 11:33 AM
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Yes, electricity can be used for lots of things. It has high exergy. On the other hand, heating and cooling doesn't require high exergy. Why use a high exergy source to do a low exergy job? Maybe it could be justified if heating and cooling were a small load, but it isn't. It's around half of all building ...
Posted By M Keith Sharp 05-27-2024 11:04 AM
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Sorry for the delay in responding. Other commitments got in the way, including the ASES conference. "it can only be implemented on new construction." Simply not true. Sure, there are some existing buildings for which using ambient conditioning would be challenging or essentially impossible. Lack of ...
Posted By M Keith Sharp 04-03-2024 10:33 AM
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Debbie, Great idea. I copied below the Key Messages from our workshop white paper. By infographic, do you mean something with fewer words and more pictures? Good plan to involve Solar Building Division members. Feedback welcomed from this forum, as well. Key Messages 1. Ambient energy (from ...
Posted By M Keith Sharp 04-03-2024 07:18 AM
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Sure, thanks for asking. A large part of the policy impact comes down to federal research priorities, particularly at DOE. There was a comprehensive program of research, development, demonstration and outreach on passive solar and solar thermal systems that was cut by Reagan. Those were tough times ...
Posted By M Keith Sharp 04-02-2024 06:48 AM
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Kat, Buildings account for nearly half of US energy use and a large fraction of greenhouse gas emissions. There are tremendous opportunities for reducing the impact of buildings by adopting policies that promote the use of ambient energy for a wide range of applications, including heating, cooling, ...
Posted By M Keith Sharp 03-21-2024 11:58 AM
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Luther, Thanks so much for all you do! Keep up the good work. Keith ------------------------------ M Keith Sharp Emeritus Professor Louisville KY ------------------------------
Posted By M Keith Sharp 03-20-2024 02:18 PM
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ASES is 70 years old this year! Thanks to Carly for the email announcement. 1954 was the year that Bell Labs patented a PV cell, but it was also the year that Farrington Daniels took his first UNESCO-funded trip around the world to discuss and demonstrate solar thermal devices, which were better known ...
Posted By M Keith Sharp 01-08-2024 02:10 PM
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Elias, You probably know about PVWatts, also. I wouldn't be surprised if the tools you listed incorporate PVWatts for their calculations. The thing I like about PVWatts is that it is so simple - just pick a location and enter a few inputs. Best, Keith ------------------------------ M Keith ...
Posted By M Keith Sharp 01-08-2024 02:02 PM
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Thanks for the article. Pessimistic, but that is reality. We have a lot of work to do. ------------------------------ M Keith Sharp Emeritus Professor Louisville KY ------------------------------
Posted By M Keith Sharp 12-22-2023 09:43 AM
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https://www.govinfo.gov/content/pkg/CHRG-112hhrg80856/html/CHRG-112hhrg80856.htm#:~:text=According%20to%20this%20Oak%20Ridge,power%20collapse%20from%20electromagnetic%20pulses. "According to this Oak Ridge Study, the collapse of our power system could impact 130 million Americans, require 4 to 10 years ...
Posted By M Keith Sharp 12-21-2023 09:52 PM
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Fitch, I will take your word for it that there is a 1% chance of an EMP event. Just want to point out that in many parts of the country, there are already higher percentage power disruptions (from tornadoes, hurricanes, floods, accidents, even just freezing weather in TX). Resilience to power outages ...
Posted By M Keith Sharp 11-22-2023 09:44 AM
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Tim, Thanks for the meeting links. Europe seems to be ahead of us in solar heating of buildings. Happy Thanksgiving to all! ------------------------------ M Keith Sharp Emeritus Professor Louisville KY ------------------------------
Posted By M Keith Sharp 11-20-2023 10:32 PM
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Tim, Please read my article. The Warren/Saunders house in Boxborough, MA (a cold and cloudy climate) was built in 1986, and has remained comfortable all these years without a furnace or air conditioner. You are right, the house has lots of thermal mass. Modern systems need less. The Riggins house ...
Posted By M Keith Sharp 11-20-2023 10:14 PM
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The Riggins house in my Solar Today article cost 8% more than a code-built house. This includes 99% passive solar heating, 100% passive cooling and 99% solar hot water. It also includes a heat pump backup, which hasn't been needed (used for 5 hours total in the first five years), because they also have ...
Posted By M Keith Sharp 11-20-2023 02:33 PM
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Passive solar heating systems typically use the south-facing wall, not the roof. Walls are almost always vertical. See the sketch below. Back in the day, a number of communities included solar access (for the south wall for passive solar heating, not the roof for PV) in the building codes for new development. ...
Posted By M Keith Sharp 11-20-2023 01:20 PM
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On a vertical surface, you get more solar radiation in the winter than in the summer. This is quite convenient for passive solar heating systems, which contrary to popular belief, can be designed to not need a backup. Amen to the discussion on planned obsolescence! ------------------------------ ...