Energy consumption

Energy consumption
Equation Description:
Calculate the energy consumed for each hour
Equation Contents:

double
energy_sum = 0;
DateTime cur_time;
bool is_first_time = true;
public double HourEnergy(double Input)
{
    if (is_first_time)
    {
        cur_time = this.StartTime;
        energy_sum = 0;
        is_first_time = false;
    }
    else
    {
        DateTime pre_time = cur_time;
        cur_time = cur_time.AddSeconds(this.SampleInterval);
        if (cur_time.Hour != pre_time.Hour)
        {
            energy_sum = 0;
        }
        else
        {
            energy_sum += this.Channels[0].Measurement * this.Channels[1].Measurement * this.SampleInterval;
        }
    }
    return energy_sum;
}