Unable to perform assignment because the left and right sides have a different number of elements. Kindly Help...Many thanks!

I am working on a large data set(8760hrs)from an excel file:

SolRad=RaWD(:,2); WSpd =RaWD(:,3);...Grid =RaWD(:,6); etc.

I prepared the following program (extracts), but when running I got the above error:

Ppv = ones(1,8760);
    for t=1:8760
    Ppv(t)=epv*K(1)*SolRad(t);       % power supplied by PV panels [kW] 
    end
 Cpv=ipv*K(1);

   Pw = ones(1,8760);  
      for t=1:8760
       Pw(t)=0.5*Cp*rho*effw*K(2)*(WSpdon(t)^3);            % Rated power of wind generator [kW]
      end
      Cw=iw*K(2);

Pg(t)= Ppv(t)+Pw(t)+Pgrid +PH(t);
   SOC =ones(1,t);    % Preallocation for speed
   DPS = ones(1,t);    % Preallocation for speed
   EPG = ones(1,t);
    if Pg(t)>=Pl(t)/effI  % excess energy stored in the battery 
        SOC(t)=(SOC(t-1)*(1-dh))+((Pg(t)-(Pl(t)/effI))*ebc);
        DPS(t)=0;
    if    SOC(t)>=SOCmax
        SOC(t)=SOCmax;
        EPG(t)=Pg(t)-((Pl(t)/effI)+(((SOCmax-SOC(t-1)))/ebc));
    end

[Walter Roberson]

Which line is the error occurring on? What are the size() of each variable mentioned on that line?

Are you possibly using global variables or persistent? It is not uncommon with global or persistent variables for an initialization to have been missed, which leaves the variable empty, and then when you use that variable in an expression the calculated value typically becomes empty.

[David Konneh]

Ppv = ones(1,8760);
    for t=1:8760
    Ppv(t)=epv*K(1)*SolRad(t);       % power supplied by PV panels [kW] 
    end

[David Konneh]

I am not using global variables...

[Guillaume]

Please give us the full text of the error message. Everything in red.

Unrelated to the error: None of the loops in the code you show are necessary. The first 4 lines you show can be replaced by:

PPV = epv*K(1)*SolRad;  %no loop needed

assuming that SolRad is a 8760 element vector and epv is scalar. Similarly, the 2nd loop can be replaced by

Pw = 0.5*Cp*rho*effw*K(2)*Wspdon.^3;  %note that .^ is required instead of ^

In addition the code after the second looks like it should have been in another loop. That loop would be more difficult to remove.

[Walter Roberson]

I predict that size(epv) is not 1 x 1.