jqkeller · HackerTrans

8 jaar geledendiscuss

My understanding of their data innovation is on the marketing side. What I heard is they're narrowing their marketing to only homes on heating oil or propane, essentially not going after houses on the natural gas infrastructure. The gas distribution data at the residence level is not super public.

jqkeller

8 jaar geledendiscuss

Ground Source (geothermal) heat pumps are not new, but Dandelion is doing interesting/innovative things. Here is my understanding from keeping track of what they're up to for a little while.

First they've developed a new drilling rig to try and drop the drilling time, cost and mess by 10x. Call the drilling traditionally 50% of the cost. This is for doing vertical bore holes, instead of horizontal trenches.

Second, they're targeting/marketing directly to home owners in cold regions who use heating oil for heating. The data collection/marketing is ground breaking for residential HVAC, but I would guess probably nothing too amazing compared to any modern web company.

Third, they're bringing modern financing to the ground source heat pump space. Similar to solar leases/PPA's is my understanding.

jqkeller

10 jaar geledendiscuss

Are you helping utilities that don't have an API to setup one?

jqkeller

10 jaar geledendiscuss

I've worked on a few street light retrofit projects and the AMA warning is a little overblown and frankly immediately outdated.

This is off the cuff, but it comes down to circadian rhythms being influenced by the color of light. Before artficial light, the sunrise and sunset have a softer light with a lot more red wavelength in it. This would correspond more closely with the color of light from an incandescent, like 2500-3000 Kelvin. The mid day light has a lot more blue wavelength in it relatively, where it is much more of a White light, I think daylight is like 15,000K. The high pressure sodium, HPS, lights have an orange light in the 2,200K range. The majority of LED street lights being installed are 4000-5000K, so they have a lot more of the blue light. Essentially the blue light tricks your brain into thinking it's mid day and messes with your sleep patterns.

The first generations of LED street lights could really only effectively make the 4000-5000K light. With new generations coming out every 3 months or so though they have been able to create models that can generate the 2500-3000K warm red light, but they're not quite as energy efficienct as the 4000K lamps, maybe 10% or something. The 2500K is actually better for the Dark Sky movements as well and a lot of cities are moving to specify these warmer temperature for those reasons.

There are a whole bunch of other things going on as well. The road way lighting standards were designed around the light patterns of a HPS lamp and haven't been updated to reflect the light patterns possible with LEDs, hence a lot of LED projects have too bright of streets.

For the sleep pattern issues, when you're installing LED lights in your home, you want to put the warm lamps, 2500-3000K, lamps in bedrooms and such. Then for living spaces or offices you'd want to put the 4000K lamps to help keep you awake during the day. There are also lamps/fixtures available that will automatically tune the color output of the light to be in sync with the outdoors to help keep circadian rhythms in sync.

This company has been pushing the tunable lamps hard. http://www.planled.com/archives/portfolio-item/entraining-ci...

http://humancentriclighting.org/ This site appears to be fairly dead, but they were more of an independent group promoting it the last year or two.

jqkeller

10 jaar geledendiscuss

I was just commenting today how approachable this book makes understanding the requirements to transition to renewable energy. I would warn though that the little bit of economics and the discussions about battery storage and solar PV at the end are very dated. The exponential drop in pv prices wasn't anticipated by the author. I think if modern prices were used the 5 models at the end would look very different.

jqkeller

10 jaar geledendiscuss

Under the current regulatory schemes and market rules the low capacity factor of solar is absolutely a problem. I guess I'm saying that more flexibility for smaller systems to play in the markets will be important to increase renewable energy production. The advent of cost effective storage will obviously make the whole discussion easier.

jqkeller

10 jaar geledendiscuss

Maybe at the 100MW scale it already operates like this, but not at smaller scale. Recently I had a discussion with a county level public utility district where we were exploring building a 1-10 MW Solar system on a closed landfill. The capability existed for us to wheel the power to a load that was interested in the energy, but the smallest chunk of capacity we could buy was 1MW and the cost to wheel the power would require a >90% capacity factor to make it economical.

So the system may well exist, but I think there is benefit from some scaling down of the market rules.

jqkeller

11 jaar geledendiscuss

One of the basic arguments of this piece is that skyscrapers have a lower environmental impact than low and mid rise buildings, but that's not necessarily true.

The city of Seattle released an updated report for 2013 data on their mandated city wide energy benchmarking. http://www.seattle.gov/Documents/Departments/OSE/EBR-2013-re... I would suggest that these results may not translate well to the rest of the world, Seattle's climate is so mild it's a bit of an outlier.

Based on the data collected, mid-rise housing has a lower Energy Use intensity (EUI) than high rise housing, see page 33. Figure 22 on page 51 is also interesting because it looks like the high rise multifamily also has a lower variance than the mid-family. To me that implies there is less room for design improvement, more of the buildings are grouped around the median higher EUI. EUI is the annual energy use per area of building, typically kBtu per square foot in the states.

I found these results somewhat counter-intuitive from an Mechanical/Energy Engineer point of view until I thought about it a bit. Ideally a tall dense building has less exterior area per interior area and hence lower heat loss/gain, but in reality skyscrapers tend to have substantially more glazing(windows) than mid rise and the energy load impact of windows is substantially greater than opaque walls, say R-5 to R-20.

Also, a high rise provides the opportunity for sophisticated mechanical systems with energy recovery and efficient systems, but in reality sophisticated systems are complicated, often poorly implemented and difficult to maintain leading to excessive energy consumption.

Everything can always be designed better in the future, but I would suggest the data doesn't necessarily support that the density skyscrapers bring improves their environmental impact. Granted I'm not taking into account any of the external factors like reduced commutes, transit density, infrastructure density, etc.

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