Wisconsin Focus On Energy is the only utility energy efficiency program offering rebates for conversion of desktop systems to thin client that I'm aware of - and it should be noted that the program is a limited pilot.
I'm ultimately very hopeful that utilities will be able to promote this technology as a deemed rebate offering, paying a set rebate for each desktop converted. However, let's take a moment to look at the challenges in developing a program of that type.
As with any measure, utilities need to know how much energy is being saved through improved efficiency of one system compared to another. This is pretty complicated for thin client.
The "before" case is a fleet of desktop computers that have a pretty variable use pattern. For a given business type (institutional, corporate, call center, etc.), how many of 100 computers are on, and for how long on average over a long period? Next, how much do the machines use while active, and in sleep mode? What about differences dependent on the age and configuration of the machines?
Next, what happens back in the data center with the servers that are now hosting the desktop workloads? How many desktops can a server host, and what is the use profile of that server? What about the need for more network-attached storage? And the power needed to provide power and cool IT equipment in a data center environment that is more significant than the supporting cooling in an office environment?
Are thin client systems more expensive to purchase than a fleet of desktop equipment? By how much? Should rebates be paid only for conversions, or for new installations?
Don't let this seem like we have an insurmountable challenge. On the contrary, this is a technology where some prudent studies could answer these questions, and in my opinion, a program model could be developed that might interest a large number of utilities.
Who is going to do the work? Climate Savers Computing? Vendors of thin client systems? The EPA? Right now it is utilities like PG&E asking the questions, and better still, Wisconsin Focus on Energy stepping out there and testing the market.