Thursday, August 18, 2016

Solar Power Now Worth up to Triple the Cost of Grid Power in CO

This is big news for photovoltaic solar customers in Colorado.

I first proposed this in 2007.  Xcel then tried Smart Grid City which they bungled.

Xcel is finally letting us benefit from the advantages of:


"Net Metering Time of Use (TOU)
COSEIA and other solar parties scored a win with the agreement that  extra energy generated by solar systems in a given month can be rolled over as a monetary credit that recognizes the value of the energy at the time it was generated. The credit will be used to offset the bill for consumption the next month and can continually roll over. Those who have elected to cash out extra production will still have that option. "

(From a COSEIA email announcement of the settlement)

Time Periods:
On Peak:       2 PM through 6 PM (weekday, non-holiday)
Off Peak:       9 PM through 9 AM
Shoulder:      All Other Hours

Price per kilowatt-hour (kwh): 
                                Summer                     Winter
On Peak:                  $0.13814                   $0.08880
Shoulder:                 $0.08420                   $0.05413
Off Peak:                  $0.04440                   $0.04440

For example, if your PV system generates 10 kwh between 2 pm and 6 pm, Xcel must give you a credit of $1.38.
But if you can use the same 10 kwh during off peak hours, it will only cost you $0.44.

Some of the takeaways:

1.  Solar systems will earn more money if they face to the southwest instead of due south.
2.  Homes in Colorado can now benefit from smart timers and products like the Tesla Powerwall.
3.  The demand peak for power occurs at 4pm, which doesn't align with peak solar production. Battery storage is the key to solving this problem, hence the Gigafactory and V2G.

Note that there are a bunch of fees and charges on your utility bill that make it difficult to see your actual cost per kwh.  This issue killed TOU rates the first and second time around.


Thursday, June 16, 2016

Now You Can Affordably Tell if the Air in Your House is Healthy

Nate Adams has tested some of the affordable consumer grade indoor air quality (IAQ) monitors:
http://energysmartohio.com/blog/which-indoor-air-quality-monitors-are-best-and-why

UDATE:  I bought the Foobot, and it will go into our new homes to see if the initial air quality is acceptable. 

With all the new materials and paint, etc., the initial air quality can be suspect.

Monday, June 6, 2016

Low Energy Carriage House Under Construction

After a painfully long permitting process, GBID's "Tandem House" at 2268 S Acoma (off the alley) is under construction.

Design Highlights:


1.  Double stud "Shirley Wall" construction to meet superinsulation goals.


2.  Insulated forms for stem walls.


3.  No natural gas needed for the house.


4.  Heated and cooled with one ductless minisplit heat pump.


5.  Passivhaus air tightness goal, (0.6 ACH 50)


6.  Fluid-applied Vapor Permeable Air Barrier.


7.  Grid tied PV system for net zero yearly energy usage.


8.  Induction range for cooking.


9.  Ductless heat recovery ventilator.


10. Ventless heat pump clothes dryer.


11. Complies with Denver's new Tandem House zoning form.  The home can be legally sold seperately from the home in front.






Sunday, May 8, 2016

Tiny Houses and Sustainability

A new study is out on the topic of tiny house feasibility for urban settings.

Tiny Houses could be a large part of the solution to affordable housing in Denver.

Here at GBID we are continuing to gain experience in the low cost housing sector by renting out fiberglass egg trailers parked in back yards.  These trailers have full utility hookups.

We just rented another one for $450/month after a tenant moved out.  Here's a one-minute "exit interview" with Dave after his 6 month stay in the Scamp.   https://www.youtube.com/watch?v=bvH-ufaR4u4

This price point makes it one of the few solutions for someone trying to survive on minimum wage or Social Security alone.

Sunday, April 10, 2016

LED Lighting is evolving quickly

Conturrent puts low energy LED lighting into a less expensive total package.

This is starting to deliver on LED's potential to deliver a lower first cost as well as using a fraction of the electricity of older systems.

"Conturrent uses so little energy that it doesn't need all the protective hardware of traditional lighting systems to keep you safe from dangerous (110v) AC voltage."




Wednesday, August 5, 2015

Successful Tiny House !!

The Tiny House movement deserves some study as a sustainable housing strategy.

Historically, the biggest problem is finding a place to put your tiny house.  Zoning and building codes have made it nearly impossible to do legally.

The town of Spur, TX, made a conscious commitment to allow them, so a guy named Conor had one built and installed in Spur.

He documented his schedule and costs

Here's the detailed story with all the cost information, but I will summarize:

It cost a total of $47k, which includes the cost of the house built on a trailer of $24.7k.  He thinks that a Tumbleweed home would have been double that.

The best news is now his monthly cost of housing is just $4.21 for the property tax.   Utilities run about $227.  Food is on top of that.

Conor is completely happy with the final result, and gives kudos to the open-minded town of Spur:  "I really do applaud Spur for opening up their town to people like me and houses like this one."

There's one more hero in this story.  Tom Meyers is the building code official that prodded the IRC into eliminating the 120 sq. ft. minimum requirement for habitable space.


Other towns have seen the light, joining Spur recently is Walsenburg, CO, and Osprey, FL


To Conor and myself, paying lot rent of $200+ at a tiny house community just doesn't make any sense if you are trying to be self-reliant and minimize your long term expenses.  Eventually, that tiny house community will be eliminated, just like cities have been getting rid of mobile home parks since the 1970s.

Friday, July 24, 2015

Heat Pump Dryer Update III

The LG heat pump dryer is finally available.

Heat pump dryers are a big deal because they use a lot less electricity than conventional dryers.

The Whirlpool dryer is also ventless.   The LG requires a vent because of its "quick cycle".

"While the Whirlpool only has a single 1,300 watt element and lacks a vent, we found it to be faster than the LG on nearly every cycle. For instance, the LG's Normal cycle took upwards of two hours when we used the heat pump, while the Whirlpool's took just under an hour and a half. The tradeoff? The Whirlpool's fastest cycle was around 45 minutes, while the LG's Quick cycle took only 25." - - Jonathan Chan at Reviewed.com

 Conventional vented dryers actually cause your house's heating system to approximately double the amount of energy used by the dryer in winter.  That's because the air blown outside by the dryer has to be replaced by cold outside air.

The Whirlpool heat pump dryer is currently backordered at Home Depot, which could mean either the demand is huge or they are having production problems.

UPDATE:  6/6/2016 -- The Whirlpool  WED99HEDW  is again backordered at HD, and they slashed the price by 44% to $943.   Again, this could mean demand is huge or it's being phased out due to poor sales or field problems.    Since the Home Depot reviews were quite good, I bought one.  It will eventually pay for itself.