Merge branch 'apply_ratchets_to_per_kw_charges' of https://github.com/NREL/ssc into develop

Author: brtietz

shared/lib_utility_rate.cpp

@@ -211,6 +211,7 @@ double UtilityRateForecast::forecastCost(std::vector<double>& predicted_loads, s
     }
 
 	// Get previous peak cost - may need to run two months
+    rate->set_billing_demands();
 	double previousDemandCharge = rate->get_demand_charge(month, year);
     double previousEnergyCharge = 0;
     if (rate->enable_nm)
@@ -268,6 +269,7 @@ double UtilityRateForecast::forecastCost(std::vector<double>& predicted_loads, s
 	}
 
     // Compute new peak cost - may need to run two months
+    rate->set_billing_demands();
     double newDemandCharge = rate->get_demand_charge(month, year);
     // If forecast length is 1, restartMonth won't be triggered on the next forecast. Trigger it now
     if (crossing_month && n == 1)

shared/lib_utility_rate_equations.cpp

@@ -129,11 +129,13 @@ rate_data::rate_data() :
 	dc_hourly_peak(),
 	monthly_dc_fixed(12),
 	monthly_dc_tou(12),
-    en_ec_billing_demand(false),
+    uses_billing_demand(false),
+    en_billing_demand_lookback(false),
     prev_peak_demand(12),
-    ec_bd_lookback_percents(12),
-    ec_bd_minimum(0.0),
-    ec_bd_lookback_months(1),
+    bd_lookback_percents(12),
+    bd_minimum(0.0),
+    bd_lookback_months(1),
+    bd_tou_periods(),
     billing_demand(12),
 	tou_demand_single_peak(false),
     enable_nm(false),
@@ -160,11 +162,13 @@ rate_data::rate_data(const rate_data& tmp) :
 	dc_hourly_peak(tmp.dc_hourly_peak),
 	monthly_dc_fixed(tmp.monthly_dc_fixed),
 	monthly_dc_tou(tmp.monthly_dc_tou),
-    en_ec_billing_demand(tmp.en_ec_billing_demand),
+    uses_billing_demand(tmp.uses_billing_demand),
+    en_billing_demand_lookback(tmp.en_billing_demand_lookback),
     prev_peak_demand(tmp.prev_peak_demand),
-    ec_bd_lookback_percents(tmp.ec_bd_lookback_percents),
-    ec_bd_minimum(tmp.ec_bd_minimum),
-    ec_bd_lookback_months(tmp.ec_bd_lookback_months),
+    bd_lookback_percents(tmp.bd_lookback_percents),
+    bd_minimum(tmp.bd_minimum),
+    bd_lookback_months(tmp.bd_lookback_months),
+    bd_tou_periods(tmp.bd_tou_periods),
     billing_demand(tmp.billing_demand),
 	tou_demand_single_peak(tmp.tou_demand_single_peak),
     enable_nm(tmp.enable_nm),
@@ -215,37 +219,64 @@ bool rate_data::check_for_kwh_per_kw_rate(int units) {
 
 double rate_data::get_billing_demand(int month) {
     int m = 0;
-    double billing_demand = ec_bd_minimum;
-    int prev_yr_lookback = 11 - (ec_bd_lookback_months - month); // What month do we stop looking back in the prev yr?
+    double billing_demand = bd_minimum;
+    int prev_yr_lookback = 11 - (bd_lookback_months - month); // What month do we stop looking back in the prev yr?
 
     for (m = 11; m >= prev_yr_lookback && m >= 0; m--) {
-        double ratchet_percent = ec_bd_lookback_percents[m] * 0.01;
+        double ratchet_percent = bd_lookback_percents[m] * 0.01;
         double months_demand = prev_peak_demand[m] * ratchet_percent;
         if (months_demand > billing_demand) {
             billing_demand = months_demand;
         }
     }
 
     int start_month = 0;
-    if (month >= ec_bd_lookback_months) {
-        start_month = month - ec_bd_lookback_months;
+    if (month >= bd_lookback_months) {
+        start_month = month - bd_lookback_months;
     }
 
+    int idx = 0;
     for (m = start_month; m <= month; m++) {
-        double ratchet_percent = ec_bd_lookback_percents[m] * 0.01;
-        double months_demand = m_month[m].dc_flat_peak * ratchet_percent;
-        if (months_demand > billing_demand) {
-            billing_demand = months_demand;
+        idx = 0;
+        for (int p : m_month[m].dc_periods) {
+            if (bd_tou_periods.at(p)) {
+                double ratchet_percent = bd_lookback_percents[m] * 0.01;
+                double months_demand = m_month[m].dc_tou_peak[idx] * ratchet_percent;
+                if (months_demand > billing_demand) {
+                    billing_demand = months_demand;
+                }
+            }
+            idx++;
         }
     }
 
-    if (m_month[month].dc_flat_peak > billing_demand && m_month[month].use_current_month_ratchet) {
-        billing_demand = m_month[month].dc_flat_peak;
+    if (m_month[month].use_current_month_ratchet) {
+        idx = 0;
+        for (int p : m_month[month].dc_periods) {
+            if (bd_tou_periods.at(p)) {
+                double months_demand = m_month[month].dc_tou_peak[idx];
+                if (months_demand > billing_demand) {
+                    billing_demand = months_demand;
+                }
+            }
+            idx++;
+        }
     }
 
     return billing_demand;
 }
 
+void rate_data::set_billing_demands() {
+    for (int m = 0; m < (int) m_month.size(); m++) {
+        double flat_peak = m_month[m].dc_flat_peak;
+        if (en_billing_demand_lookback) {
+            // If ratchets are present the peak used here might be the actual peak, or something based on a previous month.
+            flat_peak = get_billing_demand(m);
+        }
+        billing_demand[m] = flat_peak;
+    }
+}
+
 void rate_data::setup_prev_demand(ssc_number_t* prev_demand) {
     for (size_t i = 0; i < prev_peak_demand.size(); i++) {
         prev_peak_demand[i] = prev_demand[i];
@@ -277,13 +308,8 @@ void rate_data::init_energy_rates(bool gen_only) {
                 std::vector<size_t> tier_numbers;
                 std::vector<double> tier_kwh;
 
-				// track monthly peak to determine which kWh/kW tier
-                double flat_peak = m_month[m].dc_flat_peak;
-                if (en_ec_billing_demand) {
-                    // If ratchets are present the peak used here might be the actual peak, or something based on a previous month.
-                    flat_peak = get_billing_demand(m);
-                }
-                billing_demand[m] = flat_peak;
+				// Monthly billing demand is computed prior to this loop
+                double flat_peak = billing_demand[m];
 
                 // get kWh/kW break points based on actual demand
                 for (size_t i_tier = 0; i_tier < m_month[m].ec_tou_units.ncols(); i_tier++)
@@ -805,7 +831,7 @@ void rate_data::setup_demand_charges(ssc_number_t* dc_weekday, ssc_number_t* dc_
 	}
 }
 
-void rate_data::setup_ratcheting_demand(ssc_number_t* ratchet_percent_matrix)
+void rate_data::setup_ratcheting_demand(ssc_number_t* ratchet_percent_matrix, ssc_number_t* bd_tou_period_matrix)
 {
     // Error checked in SSC variables
     size_t nrows = 12;
@@ -814,10 +840,16 @@ void rate_data::setup_ratcheting_demand(ssc_number_t* ratchet_percent_matrix)
     ratchet_matrix.assign(ratchet_percent_matrix, nrows, ncols);
 
     for (int i = 0; i < nrows; i++) {
-        ec_bd_lookback_percents[i] = ratchet_matrix.at(i, 0);
+        bd_lookback_percents[i] = ratchet_matrix.at(i, 0);
         m_month[i].use_current_month_ratchet = ratchet_matrix.at(i, 1) == 1;
     }
 
+    nrows = m_dc_tou_periods.size();
+    util::matrix_t<double> tou_matrix(nrows, ncols);
+    tou_matrix.assign(bd_tou_period_matrix, nrows, ncols);
+    for (int i = 0; i < nrows; i++) {
+        bd_tou_periods.emplace((int) tou_matrix.at(i, 0), tou_matrix.at(i, 1) == 1.0);
+    }
 }
 
 void rate_data::sort_energy_to_periods(int month, double energy, size_t step) {
@@ -881,7 +913,7 @@ ssc_number_t rate_data::get_demand_charge(int month, size_t year)
 	ssc_number_t charge = 0;
 	ssc_number_t d_lower = 0;
 	ssc_number_t total_charge = 0;
-	ssc_number_t demand = curr_month.dc_flat_peak;
+	ssc_number_t demand = billing_demand[month];
 	bool found = false;
 	for (tier = 0; tier < (int)curr_month.dc_flat_ub.size() && !found; tier++)
 	{
@@ -915,11 +947,19 @@ ssc_number_t rate_data::get_demand_charge(int month, size_t year)
 		d_lower = 0;
 		if (tou_demand_single_peak)
 		{
-			demand = curr_month.dc_flat_peak;
+            // If billing demand lookback is not enabled, this will be the flat peak
+			demand = billing_demand[month];
 			if (curr_month.dc_flat_peak_hour != curr_month.dc_tou_peak_hour[period]) continue; // only one peak per month.
 		}
-		else if (period < curr_month.dc_periods.size())
-			demand = curr_month.dc_tou_peak[period];
+        else if (period < curr_month.dc_periods.size()) {
+            int period_num = curr_month.dc_periods[period];
+            if (en_billing_demand_lookback && bd_tou_periods.at(period_num)) {
+                demand = billing_demand[month];
+            }
+            else {
+                demand = curr_month.dc_tou_peak[period];
+            }
+        }
 		// find tier corresponding to peak demand
 		found = false;
 		for (tier = 0; tier < (int)curr_month.dc_tou_ub.ncols() && !found; tier++)

shared/lib_utility_rate_equations.h

@@ -23,6 +23,7 @@ OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #ifndef _LIB_UTILITY_RATE_EQUATIONS_H_
 #define _LIB_UTILITY_RATE_EQUATIONS_H_
 
+#include <map>
 #include <vector>
 
 #include "../ssc/core.h"
@@ -113,11 +114,13 @@ class rate_data {
 	std::vector<ssc_number_t> monthly_dc_fixed;
 	std::vector<ssc_number_t> monthly_dc_tou;
 
-    bool en_ec_billing_demand; // Enable billing demand lookback percentages for kWh/kW energy charges
+    bool uses_billing_demand; // Has a energy rate with kWh/kw AND/OR has a demand charge. If false, en_billing_demand_lookback must be false
+    bool en_billing_demand_lookback; // Enable billing demand lookback percentages
     std::vector<ssc_number_t> prev_peak_demand; // Set before calling init_energy_rates
-    std::vector<ssc_number_t> ec_bd_lookback_percents;
-    double ec_bd_minimum;
-    int ec_bd_lookback_months;
+    std::vector<ssc_number_t> bd_lookback_percents;
+    double bd_minimum;
+    int bd_lookback_months;
+    std::unordered_map<int, bool> bd_tou_periods;
     std::vector<ssc_number_t> billing_demand; // Store locally for ssc outputs
 
 	bool tou_demand_single_peak;
@@ -142,11 +145,12 @@ class rate_data {
     /* Optional function if demand charges are present */
 	void setup_demand_charges(ssc_number_t* dc_weekday, ssc_number_t* dc_weekend, size_t dc_tou_rows, ssc_number_t* dc_tou_in, size_t dc_flat_rows, ssc_number_t* dc_flat_in);
     /* Optional function if energy charges use a ratchet for the billing demand */
-    void setup_ratcheting_demand(ssc_number_t* ratchet_percent_matrix);
+    void setup_ratcheting_demand(ssc_number_t* ratchet_percent_matrix, ssc_number_t* bd_tou_period_matrix);
 
     void setup_prev_demand(ssc_number_t* prev_demand);
     /* call ur_month.update_net_and_peak before this, otherwise you'll get low values back */
     double get_billing_demand(int month);
+    void set_billing_demands(); // Runs get_billing_demand and updates the billing_demand structure
 
     /* Populate ur_month objects from those filled out in setup_energy_rates. Called annually in cmod_utility_rate5, other classes may reset ur_month directly
        Can be called right away to create the vectors, but for kWh/kW rates needs to be called once after ur_month.update_net_and_peak to be accurate */