In accordance with Section A of the conditions of approval that were issued by the Illinois Commerce Commission in its order regarding the Ameren acquisition of CILCO from AES in February 2003, Ameren was required to identify potential sites for the development of additional generation within Illinois. The exact wording of the condition is inset below for reference.

• A. 1) List of Preferred Generator Sites—Applicants will develop and make available, no later than 30 days after closing of the transaction, a list of sites or areas for generation within the CILCO, AmerenUE/Illinois, and AmerenCIPS service territories (“Service Territories”) that are physically proximate to electric transmission facilities, gas delivery facilities, and water resources. Nothing herein shall require Applicants to guarantee actual availability of gas or water to the sites/areas. In developing the list of preferred sites/areas, Applicants will analyze their electrical networks and identify sites/areas where new facilities could connect to the transmission system so as to maximize power delivery from the generating facility while minimizing the need for interconnection facilities or transmission network upgrades. Applicants will update the list and related information at least annually, through 2006. At the time of each update, Applicants will provide list and related information to the Director of ICC’s Energy Division. The current updated copy of the list and related information will be made available in electronic format and will be publicly posted on the applicable RTO OASIS (or, prior to participation in an RTO, on the MAIN OASIS).

The Ameren methodology for reviewing potential sites included an analysis of existing electrical busses within the systems of AmerenUE, AmerenCIPS, and AmerenCILCO. These busses could be new interconnection points for generation, and in any event, can serve as reasonable electrical equivalents in the event potential generation is located nearby. Existing electrical models, which are posted on the MAIN OASIS, were updated for the 2004 study year. A linear analysis using base flows and contingency flows was performed with modeled transfers from each potential site to five Illinois utility control areas (AmerenUE/CIPS, AmerenCILCO, City Water Light & Power, Commonwealth Edison, and Illinois Power) taken one at a time. The ICC order specifically states that the sites should maximize power delivery from the potential generation facility. Since the ability of a generator to deliver power is a function of transmission capability, Ameren included in the analysis the presence of transmission reservations. These transmission reservations include those already confirmed to be flowing in 2004 as well as those that will have expired before then but that are entitled to automatic renewal (“Rollover rights”) by FERC order.

The results of these studies indicate that existing third party and Ameren transmission constraints limit generation on Ameren sites to 50 MW or less. It should be noted that the analysis assumed that the reduced ability to transfer to any of the five control areas limited that site. One third-party constraint at Quad Cities restricted a preponderance of transactions. There are currently ongoing discussions among transmission providers to resolve this limit. Therefore, the analysis was rerun without the inclusion of this constraint. Based on the assumption that the Quad Cities limit can be ignored, there is one site that portends to be a candidate for up to 200 MW of generation:

• E. Springfield (138 kV)

There are two substation busses at the 125 MW level:

• Mason City (138 kV)
• New Holland (138 kV)

The nearest water and gas pipeline were identified for each of these sites. Please note that the capacity of the nearest water and gas facilities to supply service to a generating plant was not a determining factor. A summary for these three sites is found below.

Bus name	Gas (nearest major pipeline)	Water
1) E Springfield 138 kV	Within 25 miles of the main PEPCO line.	City of Springfield
2) Mason City 138 kV	Over 10 miles from a radial tap off of PEPCO line which serves the greater Peoria area. Approximately 40 miles to the main PEPCO line.	30 miles from City of Springfield. 25 miles from Illinois River. Within 5 miles of Sugar Creek and Salt Creek.
3) New Holland 138 kV	Within 10 miles of a radial tap off of PEPCO line which serves the greater Peoria area. Approximately 40 miles to the main PEPCO line.	30 miles from City of Springfield. Within 5 miles of Sugar Creek and Salt Creek.

NOTES:

1. All distances are approximate.

2. PEPCO = Panhandle Eastern Pipeline Company.

Analyses of this type should only be considered as guidance. Changing generation patterns and transmission reservations will have a major impact on generation outlet and are continually changing. Potential generator developers are encouraged to submit transmission requests via the Open Access Same-time Information System (OASIS) to formally ascertain the availability of transmission capacity to deliver the output of a proposed plant. Although the analysis of the existing system does not indicate the ability to add large-scale generation facilities without significant transmission upgrades, the very magnitude of the investment in these facilities usually includes transmission outlet capacity costs as an integral part. Any proposed large-scale generation should consider an interconnection to Ameren 345 kV facilities.

Disclaimer:

Due to Ameren’s geographical location, relative location of generation and load centers, and its numerous transmission interconnections, the Ameren transmission system has unique characteristics that must be considered when connecting generation to the Ameren transmission system. The areas previously identified as prospective generating sites were considered solely on the basis of an interpretation of the ICC order as stated above.

Existing plants and proposed generation facilities that have authorized Ameren to purchase equipment or have an Interconnection Agreement with Ameren filed at FERC were considered when performing the analysis. If existing generation is retired or a proposed project is abandoned, then those sites may become desirable.

Environmental issues, water or fuel availability, or siting/zoning issues associated with a specific location are beyond the scope of this posting. Note that the need for system upgrades is highly dependent upon exact location and the magnitude of any generation addition.

New generating facilities are not precluded from interconnecting to Ameren’s transmission system at locations other than those identified. A generator’s ability to interconnect at the sites listed is not guaranteed, and interconnection at these locations may require the construction of network upgrades to the Ameren transmission system in addition to the construction of the interconnecting facilities.

Ameren does not offer to purchase the output of any generation that may be constructed at such sites, nor does Ameren warrant or otherwise guarantee the availability of firm transmission service from these sites. Both interconnection and transmission service are governed by the terms of Ameren’s Open Access Transmission Tariff.

Customers that propose to connect new generation to Ameren’s transmission system are responsible for obtaining the necessary federal and state regulatory approvals for generation facilities. Customers are also obligated to pay all costs associated with the planning, permitting, and construction of the new generating facilities. The costs of Generation Connection studies are also the Customer’s responsibility, but such cost may be subject to reimbursement by Ameren pursuant to another condition of approval in the ICC order for the Ameren acquisition of CILCO.

Furthermore, Ameren makes no representations or warranties of any kind, with respect to this information, whether express or implied, including, but not limited to, implied warranties of merchantability, fitness for a particular purpose, and non-infringement.

Ameren is not liable for any direct, indirect, incidental, consequential, special, exemplary, punitive, or other damages arising out of or relating in any way to use of the information herein. The material contained herein is for informational purposes only and is subject to change.