If any National Renewable Energy bill is passed, it could be as simple as:
"To the extent that  it is cost effective to do so, beginning in 2025 the annual retail  electric sales of each electrical corporation providing power across state lines shall  consist of qualifying electricity or renewable energy certificates in an  amount equal to at least 20% of adjusted retail electric sales."
Utah has Renewable Energy Goals as State Law.
"To the extent that  it is cost effective to do so, beginning in 2025 the annual retail  electric sales in this state of each electrical corporation shall  consist of qualifying electricity or renewable energy certificates in an  amount equal to at least 20% of adjusted retail electric sales."
http://www.le.utah.gov/UtahCode/getCodeSection?code=54-17-602
The bill that was passed:
http://le.utah.gov/~2008/bills/sbillenr/sb0202.htm
Curtis  S. Bramble, Utah State Senator (R), District 16 invited all groups effected  or interested that would sit at the table to get involved in the bill.  In this case, Senator Bramble was a consensus builder. No one voted against this bill, House or Senate. That is what we  need nationally, and it isn't happening.
Does it work? See:
http://geology.utah.gov/emp/energydata/statistics/renewables6.0/T6.8.xls