In this paper, our focus is on energy efficient coding schemes for wireless sensor networks. A source coding and modulation technique for reducing multiple access interference (MAI) as well as for reducing power consumption in MC-CDMA wireless sensor network systems is presented. In all our analysis we consider perfect power control mechanism. Source symbols are represented by a special coding, termed Minimum Energy coding (ME coding), which exploits redundant bits for saving power when transmitted via RF links with On-Off-Keying. This ME coding is applied to MC-CDMA sensor network systems in order to reduce MAI as well as to reduce power consumption. The proposed method is aptly suitable for wireless sensor video node in application of video coding.