the matrix only works till days= 16 then when the days=17 or bigger the output is 0 on all the values in the matrix
% solar irradiation on a HORIZONTAL SURFACE
Cn = 0.7; % Clearance index
I0 = 1353; % Solar constant
latitude = -34.005133; % Latitude of the location
days =31; % Number of days in the month
hours = 24; % Number of hours in a day
% Initialize matrices to store results
dec_deg = zeros(days, 1); % Declination angles in degrees
DNI = zeros(days, hours); % Direct Normal Irradiation
DHI = zeros(days, hours); % Diffuse Horizontal Irradiance
GHI = zeros(days, hours); % Global Horizontal Irradiance
for n = 1:days
% Calculate declination angle for the day (in degrees)
dec_deg(n) = 23.45 * sind((360/365) * (n + 284));
% Convert declination angle from degrees to radians
dec_rad = deg2rad(dec_deg(n));
for time = 1:hours
% Calculate hour angle
h = (12 – time) * 15; % Hour angle in degrees
h_rad = deg2rad(h); % Hour angle in radians
% Calculate diffuse factor (Cs)
Cs = 0.095 + 0.04 * sin(deg2rad(360/365) * (n – 100));
% Calculate extraterrestrial solar irradiation (I)
I = I0 * (1 + 0.034 * cos(deg2rad(360 * n / 365.25)));
% Calculate atmospheric optical depth (k)
k = 0.174 + 0.035 * sin(deg2rad((360/365) * (n – 100)));
% Calculate solar altitude angle (alt)
Lat = deg2rad(latitude); % Latitude angle in radians
alt = asin(cos(Lat) * cos(dec_rad) * cos(h_rad) + (sin(Lat) * sin(dec_rad)));
alt_deg = rad2deg(alt); % Daily Solar Altitude Angle
% Calculate air mass (AM)
AM = 1 / sin(deg2rad(alt_deg)); % Air Mass
% Calculate Direct Normal Irradiation (DNI) for the current hour
DNI(n, time) = Cn * I * exp(-k * AM);
% Calculate Diffuse Horizontal Irradiance (DHI) for the current hour
DHI(n, time) = Cs * DNI(n, time);
% Calculate Global Horizontal Irradiance (GHI) for the current hour
GHI(n, time) = (DNI(n, time) + DHI(n, time)) / 1000;
end
end
%% Format changed
format longg
% Display matrices
disp("Direct Normal Irradiation (DNI) for 31 days (24 hours each): ");
disp(DNI);
disp("Diffuse Horizontal Irradiance (DHI) for 31 days (24 hours each): ");
disp(DHI);
disp("Global Horizontal Irradiance (GHI) for 31 days (24 hours each): ");
disp(GHI);
the display is 0 in the matrix for all 31 days but when the days=16 there is an output. if days=17 the output starts to be 0% solar irradiation on a HORIZONTAL SURFACE
Cn = 0.7; % Clearance index
I0 = 1353; % Solar constant
latitude = -34.005133; % Latitude of the location
days =31; % Number of days in the month
hours = 24; % Number of hours in a day
% Initialize matrices to store results
dec_deg = zeros(days, 1); % Declination angles in degrees
DNI = zeros(days, hours); % Direct Normal Irradiation
DHI = zeros(days, hours); % Diffuse Horizontal Irradiance
GHI = zeros(days, hours); % Global Horizontal Irradiance
for n = 1:days
% Calculate declination angle for the day (in degrees)
dec_deg(n) = 23.45 * sind((360/365) * (n + 284));
% Convert declination angle from degrees to radians
dec_rad = deg2rad(dec_deg(n));
for time = 1:hours
% Calculate hour angle
h = (12 – time) * 15; % Hour angle in degrees
h_rad = deg2rad(h); % Hour angle in radians
% Calculate diffuse factor (Cs)
Cs = 0.095 + 0.04 * sin(deg2rad(360/365) * (n – 100));
% Calculate extraterrestrial solar irradiation (I)
I = I0 * (1 + 0.034 * cos(deg2rad(360 * n / 365.25)));
% Calculate atmospheric optical depth (k)
k = 0.174 + 0.035 * sin(deg2rad((360/365) * (n – 100)));
% Calculate solar altitude angle (alt)
Lat = deg2rad(latitude); % Latitude angle in radians
alt = asin(cos(Lat) * cos(dec_rad) * cos(h_rad) + (sin(Lat) * sin(dec_rad)));
alt_deg = rad2deg(alt); % Daily Solar Altitude Angle
% Calculate air mass (AM)
AM = 1 / sin(deg2rad(alt_deg)); % Air Mass
% Calculate Direct Normal Irradiation (DNI) for the current hour
DNI(n, time) = Cn * I * exp(-k * AM);
% Calculate Diffuse Horizontal Irradiance (DHI) for the current hour
DHI(n, time) = Cs * DNI(n, time);
% Calculate Global Horizontal Irradiance (GHI) for the current hour
GHI(n, time) = (DNI(n, time) + DHI(n, time)) / 1000;
end
end
%% Format changed
format longg
% Display matrices
disp("Direct Normal Irradiation (DNI) for 31 days (24 hours each): ");
disp(DNI);
disp("Diffuse Horizontal Irradiance (DHI) for 31 days (24 hours each): ");
disp(DHI);
disp("Global Horizontal Irradiance (GHI) for 31 days (24 hours each): ");
disp(GHI);
the display is 0 in the matrix for all 31 days but when the days=16 there is an output. if days=17 the output starts to be 0 % solar irradiation on a HORIZONTAL SURFACE
Cn = 0.7; % Clearance index
I0 = 1353; % Solar constant
latitude = -34.005133; % Latitude of the location
days =31; % Number of days in the month
hours = 24; % Number of hours in a day
% Initialize matrices to store results
dec_deg = zeros(days, 1); % Declination angles in degrees
DNI = zeros(days, hours); % Direct Normal Irradiation
DHI = zeros(days, hours); % Diffuse Horizontal Irradiance
GHI = zeros(days, hours); % Global Horizontal Irradiance
for n = 1:days
% Calculate declination angle for the day (in degrees)
dec_deg(n) = 23.45 * sind((360/365) * (n + 284));
% Convert declination angle from degrees to radians
dec_rad = deg2rad(dec_deg(n));
for time = 1:hours
% Calculate hour angle
h = (12 – time) * 15; % Hour angle in degrees
h_rad = deg2rad(h); % Hour angle in radians
% Calculate diffuse factor (Cs)
Cs = 0.095 + 0.04 * sin(deg2rad(360/365) * (n – 100));
% Calculate extraterrestrial solar irradiation (I)
I = I0 * (1 + 0.034 * cos(deg2rad(360 * n / 365.25)));
% Calculate atmospheric optical depth (k)
k = 0.174 + 0.035 * sin(deg2rad((360/365) * (n – 100)));
% Calculate solar altitude angle (alt)
Lat = deg2rad(latitude); % Latitude angle in radians
alt = asin(cos(Lat) * cos(dec_rad) * cos(h_rad) + (sin(Lat) * sin(dec_rad)));
alt_deg = rad2deg(alt); % Daily Solar Altitude Angle
% Calculate air mass (AM)
AM = 1 / sin(deg2rad(alt_deg)); % Air Mass
% Calculate Direct Normal Irradiation (DNI) for the current hour
DNI(n, time) = Cn * I * exp(-k * AM);
% Calculate Diffuse Horizontal Irradiance (DHI) for the current hour
DHI(n, time) = Cs * DNI(n, time);
% Calculate Global Horizontal Irradiance (GHI) for the current hour
GHI(n, time) = (DNI(n, time) + DHI(n, time)) / 1000;
end
end
%% Format changed
format longg
% Display matrices
disp("Direct Normal Irradiation (DNI) for 31 days (24 hours each): ");
disp(DNI);
disp("Diffuse Horizontal Irradiance (DHI) for 31 days (24 hours each): ");
disp(DHI);
disp("Global Horizontal Irradiance (GHI) for 31 days (24 hours each): ");
disp(GHI);
the display is 0 in the matrix for all 31 days but when the days=16 there is an output. if days=17 the output starts to be 0 matrices MATLAB Answers — New Questions