I've previously shared the first few months of output from our solar system, we turned it on at the start of September, and on a clear day we were getting around 24KWh. As the days got shorter and the Sun got lower in the sky, the clear day output dropped off, and earlier this week we hit the winter solstice, the shortest day. Wednesday was a clear day, and we generated about 16KWh, as shown in the plot below.
We have also seen the benefit of our E6-time of use rate plan. We generate electricity during the week while we are mostly out of the house at the highest rate, and use it at the cheapest rate. So we continue to be net consumers of electricity, generating between 50% and 70% of what we use, but our electricity bill is basically zero at this point. In addition, PG&E just gave us a rebate of $67 due to lower energy costs, so the standing charge of $11.50/month is zeroed out for almost six months.
We converted our gas appliances to electric, for heating water, drying clothes and cooking, and currently only use gas for the furnace that heats the house. We looked into replacing the furnace with a ground source heat pump (GSHP) but got wildly varying designs and costs from everyone we talked to so have postponed that idea. The one thing everyone agreed on was that our ducting was sub-standard, with insufficient flow for A/C and barely enough for the furnace, and it was poorly constructed using the lowest quality materials.
So we have just replaced the ducts throughout the house, changing the configuration to include separate zones for upstairs and downstairs, adding a new return path from upstairs and one extra outlet. The ducts are insulated to R8, rather than R4.2, so they don't lose heat, and they have fewer leaks and a properly designed balance of air flow into each room. This is done using something called a Manual-J calculation, and there is also an independent analysis service that verifies that everything is working correctly. The main effect of this is that we will use less propane, and have much better control over temperature upstairs. We often want to heat the bedrooms without wanting to heat downstairs to the same level, and we now have a thermostat in the main bedroom for upstairs, as well as one downstairs.
I'm planning to blog some more about GSHP options, its quite complicated....
Started in 2004. Covers anything I find interesting, like clouds, cars and strange complex music. Views expressed are my own and not those of my employers (currently AWS). See also @adrianco
Thursday, December 24, 2009
Wednesday, December 16, 2009
Global Warming
Two essential books to read: Climate Cover-Up: The Crusade to Deny Global Warming by James Hoggan - how the oil and coal industries are behind the denialist spin doctors - will make you angry. Storms of My Grandchildren: The Truth About the Coming Climate Catastrophe and Our Last Chance to Save Humanity by James Hansen - will make you scared.
James Hansen is the NASA scientist who is probably the worlds top climate expert. Industry and politicians don't want to hear the message he has been trying to get through for years, that the situation is much worse than the IPCC projections already. He provides the research background for the safe limit of 350ppm of CO2 that is being promoted by some at Copenhagen at the moment. We are already at 387ppm, and increasing rapidly, and we are seeing irreversible changes in climate as the ice melts. James is calling for a worldwide moratorium on building coal fired power plants as a first step. The oil and coal has to be left underground.
Human civilization has occurred during a time of very stable sea levels, over the last 7000 years. Before that sea levels have changed more rapidly and over a range of hundreds of feet. Human induced global warming is forcing change an order of magnitude stronger than the natural changes in climate, and is still accelerating. With very unstable sea levels, ports and coastal areas are going to flood, and it will not be possible to establish new ports on a permanent basis, as they will be flooded in turn within the lifetimes of our children and grandchildren. The huge numbers of refugees is an even bigger problem.
What can we do?
Read those two books.
Sell coastal property while there are still people who will buy it.
Don't invest in oil, coal and insurance companies.
Put up solar panels and switch from gas to electric appliances.
Sign up at the 350.org web site, join the 350org facebook group.
I get books via the Kindle service and read them on my iPhone, instant delivery, and always with me to read.
Climate Cover-Up: The Crusade to Deny Global Warming
Storms of My Grandchildren: The Truth About the Coming Climate Catastrophe and Our Last Chance to Save Humanity
A good summary of the arguments is at Skeptical Science
I have read everything I can find on this subject over the last year or two, I have an Applied Physics degree and enough science and statistics that I can tell who and what makes sense and who doesn't. Every single denier and contrarian that I have heard of is backed by the coal and oil industries, often through opaque organizations and astroturf groups with innocent sounding names. They have been exposed as liars and cherry pickers, but really they are spin doctors sowing confusion. If you listen to them you are deluding yourself, and you should be investing in real estate in Florida...
James Hansen is the NASA scientist who is probably the worlds top climate expert. Industry and politicians don't want to hear the message he has been trying to get through for years, that the situation is much worse than the IPCC projections already. He provides the research background for the safe limit of 350ppm of CO2 that is being promoted by some at Copenhagen at the moment. We are already at 387ppm, and increasing rapidly, and we are seeing irreversible changes in climate as the ice melts. James is calling for a worldwide moratorium on building coal fired power plants as a first step. The oil and coal has to be left underground.
Human civilization has occurred during a time of very stable sea levels, over the last 7000 years. Before that sea levels have changed more rapidly and over a range of hundreds of feet. Human induced global warming is forcing change an order of magnitude stronger than the natural changes in climate, and is still accelerating. With very unstable sea levels, ports and coastal areas are going to flood, and it will not be possible to establish new ports on a permanent basis, as they will be flooded in turn within the lifetimes of our children and grandchildren. The huge numbers of refugees is an even bigger problem.
What can we do?
Read those two books.
Sell coastal property while there are still people who will buy it.
Don't invest in oil, coal and insurance companies.
Put up solar panels and switch from gas to electric appliances.
Sign up at the 350.org web site, join the 350org facebook group.
I get books via the Kindle service and read them on my iPhone, instant delivery, and always with me to read.
Climate Cover-Up: The Crusade to Deny Global Warming
Storms of My Grandchildren: The Truth About the Coming Climate Catastrophe and Our Last Chance to Save Humanity
A good summary of the arguments is at Skeptical Science
I have read everything I can find on this subject over the last year or two, I have an Applied Physics degree and enough science and statistics that I can tell who and what makes sense and who doesn't. Every single denier and contrarian that I have heard of is backed by the coal and oil industries, often through opaque organizations and astroturf groups with innocent sounding names. They have been exposed as liars and cherry pickers, but really they are spin doctors sowing confusion. If you listen to them you are deluding yourself, and you should be investing in real estate in Florida...
Saturday, December 12, 2009
CMG09 - Last Time Attendee
I presented a half day training class and a paper at CMG09 in Dallas last week. I won't be at CMG10. The conference has shrunk to a few hundred attendees, mostly mainframe oriented, a few vendors, and a bunch of independent consultants. Its main value for me was to maintain and extend my social network of capacity planning and performance people. There were some useful and interesting papers, but not enough to justify a full week long conference in a very expensive hotel. CMG10 is in Orlando FL, and I can't justify traveling to the east coast for more of the same.
A few years ago I discussed with the CMG board members what was needed to keep CMG from shrinking into irrelevancy, at the time I was at eBay, and early December is the peak business level for retail industry, so very few capacity/performance experts from retail can get away at that time of year, and I suggested they move the date. The dominant industries attending CMG have been banking, insurance and finance, which have been hit hard in the recession. The other change I advocated was that CMG should be held in the Bay Area, so that it could attract a lot more people from the major Web companies and computer hardware and software companies that are based here. Unfortunately CMG is locked into a long series of Hotel commitments for several years, and can't change its plans.
So my position now, is that I will attend CMG again when it comes to me. In the meantime, I will encourage the people I met every year at CMG to attend the Velocity Conference in San Jose next June. http://en.oreilly.com/velocity2010 - the call for papers closes in January, so we have a few weeks to come up with abstracts.
A few years ago I discussed with the CMG board members what was needed to keep CMG from shrinking into irrelevancy, at the time I was at eBay, and early December is the peak business level for retail industry, so very few capacity/performance experts from retail can get away at that time of year, and I suggested they move the date. The dominant industries attending CMG have been banking, insurance and finance, which have been hit hard in the recession. The other change I advocated was that CMG should be held in the Bay Area, so that it could attract a lot more people from the major Web companies and computer hardware and software companies that are based here. Unfortunately CMG is locked into a long series of Hotel commitments for several years, and can't change its plans.
So my position now, is that I will attend CMG again when it comes to me. In the meantime, I will encourage the people I met every year at CMG to attend the Velocity Conference in San Jose next June. http://en.oreilly.com/velocity2010 - the call for papers closes in January, so we have a few weeks to come up with abstracts.
Tuesday, December 08, 2009
Heading to CMG09 in Dallas today
various talks on capacity planning in the cloud on Wed, then I'm presenting on Thurs. My slides are at http://www.slideshare.net/adrianco - this is probably my last visit to CMG, its been shrinking for a while, we will see how it looks on the ground.