Confidential Materials omitted and filed separately with the Securities and Exchange Commission.Asterisks denote omissions. The Purchase Contract No. FDCG07061 for the software of SL1500 Wind Turbine

Exhibit 10.43

Confidential Materials omitted and filed separately with the

Securities and Exchange Commission. Asterisks denote omissions.

The Purchase Contract No. FDCG07061

for the software of SL1500 Wind Turbine

This Purchase Contract is signed between

Sinovel Wind Co., Ltd (hereinafter referred to as Buyer)

Buyer’s Agent: China National Machinery & Equipment Import & Export Corporation (hereinafter referred to as Buyer’s agent)

and

Windtec Systemtechnik Handels GmbH in Austria (hereinafter referred to as Seller) in a friendly way.

Buyer and Seller agreed as follows:

[**] sets of software comprising:

The delivery price is CIF Dalian [**] EURO per set. The total contract price is CIF Dalian [**] EURO.

General Terms of Delivery issued by the Austrian Electrical and Electronics Industry Association, Ed. Jan. 2002

Warranty period is 12 months after wind turbine has arrived on the wind farm and finished the commissioning, or 18 months after the delivery (shippment-date), whichever is earlier.

The software of PLC and converter will be sent out by 1 off CD and/or email per batch, as a valid licence for the number of sets indicated therein. The delivery will be made in batches as per preliminary schedule below (shippment date):

95% of each shipment value will be paid by T/T within 14 days after each shipment date against receipt of the invoice;

5% of each shipment value, as the retention bond, shall be paid by T/T within 14 days after the expiry of the warranty period.

Note: Any applicable withholding tax according to the Austrian-Chinese-Double-Tax-Treaty will be borne by Windtec in Austria.