Hydronics for high-efficiency biomass boilers
link to .ppt presentation:
http://www.nyserda.ny.gov/All-Programs/Programs/Become-a-Contractor/Renewable-Heat-NY-Contractors
Fairly complicated. For cordwood boilers, burn fast, burn hot, and store the heat in a stratified, insulated water tank. For pellet boilers, don't overdesign the system, use lots of controls/sensors, and again store the heat in a stratified, insulated water tank.
Thursday, June 16, 2016
Thursday, February 18, 2016
Solar PV
Stats before I forget all these numbers. I had a speaker from SolarCity talk to my class early this week. Their standard module is 3'x5' (15 sq feet) with a current of 252 watts and weight of 44 pounds. So 4 modules=1 kW and covers 60 square feet. They install only on roofs that have shingles or raised seam metal. With raised seam metal they install the panels w/out roof penetration by attaching to the raised seam.
This site can give you really good estimates for your particular location. It will even let you place a rectangle around your roof and it will back-calculate about how many kW of solar modules will fit (not corrected for roof slope). http://pvwatts.nrel.gov/index.php
The northeast is not the greatest for solar PV but it's all relative. A professor from Germany told me once that Germany wasn't great for solar PV and he was right. Compared to Germany the northeast US has a lot of potential (google insolation maps for Germany and the United States).
Total costs for materials/installation of solar PV (around $5/watt) are down about 50% from when I last looked about 10 years ago. SolarCity's model (apparently) is to install with no money down by using NYSERDA/federal grants. Although many others are not a fan of govt. subsidies, I'm okay with it. Solar PV panels on roofs have so many environmental benefits compared to every other energy source. All fossil fuels-too much carbon emission; nuclear-no mechanism in place to store radioactive waste; all biomass solutions-takes away from food production; solar power towers--they're interesting but do we really want such high temperature megaplants?
SolarCity plans on producing 1 GW of modules at the plant that they're currently building in Buffalo. Assuming 15% efficiency that's 150 MW per year. As a point of reference,-------If you shut down Indian Point 2 and 3 you need to replace 2,000 MW (or 1,800 MW if you assume 90% efficiency).
The nameplate versus actual production numbers get confusing fast---Nuclear plants have a high number because they're producing energy all the time except for maintenance/fuel rod replacement. Solar PV installations have a low number because they're not producing electricity at night, during cloudy weather, etc. Also, solar insolation varies throughout the day, so effectively only 4-6 hours per day of "high-quality" sun is available. (This "high-quality" number is 1000 watts per square meter per day, which is referred to as one "sun").
This site can give you really good estimates for your particular location. It will even let you place a rectangle around your roof and it will back-calculate about how many kW of solar modules will fit (not corrected for roof slope). http://pvwatts.nrel.gov/index.php
The northeast is not the greatest for solar PV but it's all relative. A professor from Germany told me once that Germany wasn't great for solar PV and he was right. Compared to Germany the northeast US has a lot of potential (google insolation maps for Germany and the United States).
Total costs for materials/installation of solar PV (around $5/watt) are down about 50% from when I last looked about 10 years ago. SolarCity's model (apparently) is to install with no money down by using NYSERDA/federal grants. Although many others are not a fan of govt. subsidies, I'm okay with it. Solar PV panels on roofs have so many environmental benefits compared to every other energy source. All fossil fuels-too much carbon emission; nuclear-no mechanism in place to store radioactive waste; all biomass solutions-takes away from food production; solar power towers--they're interesting but do we really want such high temperature megaplants?
SolarCity plans on producing 1 GW of modules at the plant that they're currently building in Buffalo. Assuming 15% efficiency that's 150 MW per year. As a point of reference,-------If you shut down Indian Point 2 and 3 you need to replace 2,000 MW (or 1,800 MW if you assume 90% efficiency).
The nameplate versus actual production numbers get confusing fast---Nuclear plants have a high number because they're producing energy all the time except for maintenance/fuel rod replacement. Solar PV installations have a low number because they're not producing electricity at night, during cloudy weather, etc. Also, solar insolation varies throughout the day, so effectively only 4-6 hours per day of "high-quality" sun is available. (This "high-quality" number is 1000 watts per square meter per day, which is referred to as one "sun").
Sunday, January 24, 2016
Human Genome Data
The human genome data is here: http://www.ncbi.nlm.nih.gov/genome/guide/human/ I always wondered where this data was. My office is near a cell biologist professor so I asked her.
You can click on a chromosome and see the locations of genes.
APP (chromosome 21), PSEN1 (chromosome 14) and PSEN2 (chromosome 1) are genes related to familial early-onset Alzheimers. I could find all but PSEN1 on the maps; although a search shows information on PSEN1 and the location 1q42.13.
APP is the amyloid precursor protein. PSEN stands for presenilin.
A gene that can predispose people to the late-onset version of Alzehimer's is APOE (apolipoprotein E) on chromosome 19. There are 3 versions APOE2, 3 and 4. You inherit 2 of them. APOE2 lowers your risk, APOE3 has little impact on risk. However APOE4 increases your risk; one copy (3-4X); two copies (15X). 1/3 of those w/ Alzheimer's don't have the APOE4 gene and 50% of those w/ 2 copies of the APOE4 gene live to 80 w/o Alzheimer's so........??? The APOE gene is involved in many processes (inflammatory, cholesterol movement, brain blood flow).
All the above info came from "The End of Memory-a Natural History of Aging and Alzheimer's" by Jay Ingram.
You can click on a chromosome and see the locations of genes.
APP (chromosome 21), PSEN1 (chromosome 14) and PSEN2 (chromosome 1) are genes related to familial early-onset Alzheimers. I could find all but PSEN1 on the maps; although a search shows information on PSEN1 and the location 1q42.13.
APP is the amyloid precursor protein. PSEN stands for presenilin.
A gene that can predispose people to the late-onset version of Alzehimer's is APOE (apolipoprotein E) on chromosome 19. There are 3 versions APOE2, 3 and 4. You inherit 2 of them. APOE2 lowers your risk, APOE3 has little impact on risk. However APOE4 increases your risk; one copy (3-4X); two copies (15X). 1/3 of those w/ Alzheimer's don't have the APOE4 gene and 50% of those w/ 2 copies of the APOE4 gene live to 80 w/o Alzheimer's so........??? The APOE gene is involved in many processes (inflammatory, cholesterol movement, brain blood flow).
All the above info came from "The End of Memory-a Natural History of Aging and Alzheimer's" by Jay Ingram.
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